GO

NBS

PUBLICATIONS

NBSIR 84-2979

Technical Activities 1984

Center for Analytical Chemistry

A111D4 0 7 b 5 b b

R. A. Velapoldi, H. S. Hertz, and J. K. Taylor

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Measurement Laboratory

Gaithersburg, MD 20899

October 1984

Final

Issued December 1984

-QC

100

. U56

4-2979

1934

c, 2

Prepared for U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Gaithersburg, MD 20899

NBSIR 84-2979

TECHNICAL ACTIVITIES 1984

CENTER FOR ANALYTICAL CHEMISTRY

NATIONAL BUREAU OF STANDARDS

LIBRARY Crrc

D-Cttoo

R. A. Velapoldi, H. S. Hertz, J. K. Taylor

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Measurement Laboratory

Gaithersburg, MD 20899

October 1 984

Final

Issued December 1984

Prepared for U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Gaithersburg, MD 20899

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Director

TABLE OF CONTENTS

Page

I. CENTER FOR ANALYTICAL CHEMISTRY

A. Center Overviews 1 B. Voluntary Standardization and Quality Assurance 1C

1. Voluntary Standardization 10

2. Quality Assurance 10

C. Service Analyses 12

II. INORGANIC ANALYTICAL RESEARCH DIVISION

A. Division Overviews 13

B. Selected Technical Accomplishments 24

1 . Determination of Boron in Borosilicate Glasses by

Neutron Capture Gamma-Ray Activation Analysis 24

2. Neutron Depth Profiling: Development and

Intertechnique Comparisons 24

3. High Accuracy Determination of ^ 35 u j n Nondestructive

Assay Standards by Gamma-Ray Spectrometry 25

4. Accurate Multi-Element Analysis of an Aquatic

Accumulator 26

5. High Repetition Rate Tunable Laser System for

Atomic Spectroscopy 27

6. Development of a High Accuracy Spectrometer for

Laser-Enhanced Ionization 27

7. The Determination of Nickel in Petroleum Products

Using Laser-Enhanced Ionization Spectrometry 28

8. An Evaluation of the Long-Term Stability of NBS

Glass and Thin Metal Film Transmittance SRM's .... 29

9. The Use of the Box Plot to Describe Heterogeneity

of Iron Samples 29

10. Redetermination of the Atomic Weight of Gallium . . . 11. Flow-Injection for On-Line Standard Addition

Calibration Using a Wavelength-Modulated DCP

Spectrometer 31

12. Speciation of Tributyltin in Seawater

13. Physical and Chemical Properties of Aerosols Produced

by the Spark Discharge

14. Characterization of Autoionizing Levels in Beryllium

with Resonance Ionization Mass Spectrometry 3-

15. The Determination of Iron in Serum and Water by

Resonance .Ionization Isotope Dilution Mass

Spectrometry

16. High Precision Isotope Ratio Measurements of CO 2 • • . 17. Certification of Nuclear Isotopic Standard

Reference Materials

18. Determination of Trace-Level Cr(VI) in the Presence

of Cr(III) and Fe(III) by Voltammetric FlowInjection Analysis

19. The Measurement of pH and Acidity in Rainwater:

Development of a Research Material/Simulated

Rainwater

1
TABLE OF CONTENTS (Continued)

Page

20. Uranium and Sulfur Isotopic Tracers in

the Environment 39

21 . Standard Reference Materials 40

C. Outputs and Interactions 44

III. ORGANIC ANALYTICAL RESEARCH DIVISION

A. Division Overview 61

B. Selected Technical Accomplishments 74

1 . Development of a Definitive Method for Serum

Creatinine 74

2. Investigation of Factors Affecting the Selectivity of

Negative Ion Chemical Ionization Mass Spectrometry

for Isomeric Polynuclear Aromatic Hydrocarbons .... 75

3. Development of an Isotope Dilution GC/MS

Procedure for Analysis of Toxic Organics in Air

Mixtures 76

4. Photodissociation of Ions Generated by 'Soft

Ionization Techniques 76

5. Investigation of Ion/Molecule Reactions in a Triple

Quadrupole Mass Spectrometer 78

6. Analysis of the Proton and Carbon-13 NMR Spectra of

Equilibrated Digitoxose by Two-Dimensional, Chemical

Shift Correlation Methods 79

7. Identification of Metal Binding Proteins in

Polyacrylamide Gels by Neutron Activation

Studies 80

8. Squid Species Differentiated by Use of Thin Layer

Isoelectric Focusing 81

9. Determination of Pesticides and PCBs in Cod-Liver

Oil 81

10. Determination of Dioxin in Soils 82

1 1 . Development of a Laboratory Data Networking System . . 83

12. Research on Metal Chelate Columns 84

13. Influence of Physical and Chemical Parameters of

Silica Substrates on the Reversed-Phase Liquid

Chromatographic Performance of Alkyl Bonded

Phases 85

14. Optimization of Secondary Chemical Equilibria in

Liquid Chromatography 86

15. Quantitative Analysis of Complex Mixtures by

LC/MS/MS 87

16. Thermal Crosslinking Procedure for Preparing

Solvent-Stable Polymei—Film Electrodes 88

17. Electrocatalytic Reduction of Ethylene Dibromide via

Rhodium(II) Tetraphenylporphyr in Dimer Derivatized

Polymer Film Electrodes 89

18. Refinement of the Mathematical Model for Charge

Transport in Polymer-Film Electrodes 90

19. Electrochemical Characteri zation of a Series of

Metal-Di thiosquarate Complexes 91
TABLE OF CONTENTS (Continued)

Page

20. Preparation and Characterization of Reference

Materials for EPA's Water and Hazardous Waste

Program 91

21 . Certification of a Priority Pollutant Phenols in

Methanol SRM 93

22. Certification of a Diesel Particulate SRM 93

23. Certification of a Gas Chromatography/Mass

Spectrometry Performance SRM 95

C. Outputs and Interactions 96

IV. GAS AND PARTICULATE SCIENCE DIVISION

A. Division Overview 108

B. Selected Technical Accomplishments 119

1 . Development of an Accurate Calibration Standard for

the Measurement of Atmospheric Tritium 119

2. Assessment of Uncertainties in GravimetricallyPrepared Toxic Organic Gas Mixtures in the PartPer-Billion Range 120

3. Measurements of the Temperature Dependence of

Selected Infrared Band Strengths of Halocarbons

F-11 (CC1 3F) and F-12 (CC1 2 F2 ) 121

4. Development of a Cryogenic Preconcentration

Technique for the Analysis of Ultratrace Constituents

in Gas Mixtures 122

5. The Investigation of the Long-Term Stability of

Tetrachloroethylene Permeation Tubes 122

6. Development of an Improved Methanation System

for the Analysis of CO and C0 2 SRM’s 123

7. The Development of a System for Analytical

Traceability in the State Motor Vehicle

Emissions Testing Program 124

8. Advances in Carbon Isotopic Ratio Measurements by

Accelerator Mass Spectrometry 125

9. Development of a Definitive Treatment for the

Calculation of Lower Limits of Detection in

Radionuclide Monitorings 126

10. A System for Traceable Calibration of Ozone

Measurements Using the NBS Primary Ozone Photometer . 12"

11. Research in Measurement Methodology Using Diode

Laser Spectrometry and the Determination of

Spectroscopic and Kinetic Data for Reactive

Atmospheric Molecules 12"

12. Development of an Improved Procedure to Calculate

Characteristic X-ray Fluorescence Corrections

from an Electron Microprobe *2“

13. Development of an Automated Digital Image Acquisition

System for Analytical Electron Microscopy ' - 14. Comparison of Boron-10 Depth Distributions as Determined by Spreading Resistance, Secondary Ion

Mass Spectrometry , and Neutron Depth Profiling ....

i i i
TABLE OF CONTENTS (Continued)

Page

15. Development of Improved Elemental and Isotopic

Measurements of Micrometer Sized Particles by

Secondary Ion Mass Spectrometry 131

16. Evaluation of a Digital Image Analysis System for

the Secondary Ion Microanalyzer 132

17. Automated Object Identification From Digital Images . 133

18. The Detection and Identification of Surface

Organic Species by Laser Ionization Mass

Spectrometry 133

19. Comparison of Multichannel SIT Vidicon and

Monochannel Photomultiplier Detection in MicroRaman Spectroscopy 13^

20. The Certification of New Multielement Glass Standards

For Analytical Microprobes 135

21. The Analysis of Natural Product SRM's by X-ray

Fluorescence 136

22. Improvements in the Algorithm for Calculating

Fundamental Parameters in Quantitative X-ray

Fluorescence Analysis 135

C. Outputs and Interactions 138

IV
I. Center for Analytical Chemistry

Harry S. Hertz, Director

Ranee A. Velapoldi, Deputy Director

A. Center Overview

The Center for Analytical Chemistry develops and maintains the

scientific competences and the experimental facilities necessary to provide

the Nation with the basis for uniform measurements through development of

measurement methodology and reference materials and provision of measurement

services, in the field of analytical chemistry. Analytical measurements

provide a foundation for scientific and technological research and development concerning materials and their practical application. Moreover, analytical measurements are increasingly used as the basis for industrial, regulatory, and health-related decisions. The Center serves as the National

Reference Laboratory for assuring the reliability of analytical measurements.

The principal means by which the Center has served as a National

Reference Laboratory is through the development of measurement concepts and

methods, provision of quality assurance services, and certification of

Standard Reference Materials (SRM's). The ubiquity of and demand for

analytical measurements in modern society is reflected in the diversity of

SRM's produced in the Center. These reference materials are widely used in

such diverse areas as the metal and chemical industries and in clinical and

environmental laboratories. Each standard is supported by research on homogeneity and stability and is certified as to chemical composition using

the most reliable analytical methods available.

Analytical chemistry is increasingly being called upon to provide key

data for highly complex sample types - hazardous chemical and nuclear wastes,

body fluids, plant and animal tissues, foods, and high-technology materials.

Increasingly, analytical values as a function of location within a sample are needed. As the demands upon analytical chemistry become more sophisticated,

the problem of standardization becomes more challenging both in terras of the

number and the complexity of the needed measurement methods and reference

materials. As it is not reasonable to contemplate the development of SRM's

to deal with every measurement problem, the Center's program must be multifaceted, seeking a variety of avenues to influence the quality of analytical

measurements made in the United States. In addition to research publications

and the certification of reference materials, the Center exerts influence

through close contacts with various communities by means of workshops,

symposia, and participation in voluntary standards committees. Through such

contacts, priorities are established for the development of measurement

methods and the production 'of reference materials, and mechanisms are set in

place for their effective use.

NOTE: Certain commercial equipment, instruments, or materials are identified

in this report to specify adequately the experimental procedure. Suer,

identification does not imply recommendation or endorsement by t r> National Bureau of Standards, not does it imply that the materials rr equipment identified are necessarily the best available for

purpose

1
In an effort initiated in 1983, we are devoting considerable attention

in the Center to better definition of our user communities and the various

mechanisms for interacting with these communities. A major component of this

interaction is the service the Center provides as a National Reference

Laboratory. During the past year we have expanded these services; a few

examples of these activities indicate the breadth of interactions which are involved. Members of the Center staff have prepared major quality assurance

documents for the Nuclear Regulatory Commission (NRC) and the National

Oceanic and Atmospheric Administration (NOAA) on Lower Limits of Detection

and Generic Quality Assurance Guidelines for Marine Pollution Measurements,

respectively. In a meeting with the Standards Steering Committee of the

Health Industry Manufacturers' Association (HIMA) we discussed the NBS role

as a scientific liaison for the regulatory and voluntary standards communities. In several meetings with members of the Compressed Gas Manufacturers

Association, we discussed the traceability program for trace-level gas

Certified Reference Materials (CRM's). We are currently preparing a document

on the meaning of traceability to NBS chemical measurements, in general.

Finally, NBS is playing expanded quality assurance roles in a Navy-sponsored

organo-tin measurement program, a National Cancer Institute sponsored

nutrient chemoprevention study, and an FDA-sponsored program on measurement

of ethylene oxide residues. These latter measurements are of particular

interest to, and our research was directly tied to, measurement programs of

the American Institute for Medical Equipment Evaluation (an industrysponsored consortium)

Directly related to our interactions with user communities is a major

planning effort in chemical measurement services. As part of this activity,

we are seeking advice from constituents on the measurement science, measurement technology, and technology transfer needs which the Center must prepare

for today, to deliver relevant services in the late 1980's and early 1990's.

A major factor in our planning is the realization that in an era of increased

reliance on voluntary standards it is vital, in our opinion, to assure the

integrity of the measurement system through traceability to nationally

accepted measurement standards. In this era, a scientifically accurate

measurement base is the best support mechanism for both the industrial and

regulatory sectors of the communities we serve.

The program of the Center strives to achieve a balance among the

provision of currently needed standards and research efforts on new types of

standards and methods of measurement. The work of the Center is performed in

three divisions, each focusing upon specific sample types - inorganics,

organics, and gases and particles. Within each division there are several

groups representing separate analytical chemical disciplines, e.g., mass spectrometry and electrochemistry . Each division is responsible for a program in basic and applied research and maintains contacts with appropriate

communities

In the following, the major recent activities and technical directions

of the divisions and groups mentioned above are summarized. Much work in

progress is omitted but will be included in subsequent Annual Reports.

2
1. Outputs and Interactions

a. Publications

Becker, D. A., "The Recycled Oil Program - Final Report", in NBS S. P. 662,

U. S. Department of Commerce, National Bureau of Standards, Gaithersburg,

MD 20899 (1983).

Becker, D. A., Hsu, S. M., and Weeks, S. J., "Lubricating Oil Basestock Dat

and Analysis: Based on the ASTM-NBS Basestock Consistency Study", Repor

DOE/BC/1 0749-2 , U.S. Dept, of Energy, Washington, DC 20585 (Also

published as NBS S.P. 661, 1983).

Gravatt, C. C., McClendon, L. T. , and Hertz, H. S., "A Summary of Activities

Related to Offshore Drilling of Petroleum at the National Bureau of

Standards 1 97 5 ~ 1 98 1 " , Interagency Energy/Environment R & D Program Report

(1983).

Hertz, H. S., Velapoldi, R. A., and Taylor, J. K., "Technical Activities

1983", Center for Analytical Chemistry, NBSIR 83~2786.

May, W. E., Brown-Thomas , J. M., Chesler, S. N., Guenther, F. R., Hilpert, L. R. , Parris, R. M., Richie, K. L., Sonnefeld, W. J., Wise, S. A., and

Hertz, H. S. , "Interlaboratory Comparisons of Quantitative Analyses of

Individual Compounds in Simple and Complex Mixtures", in Advanced

Techniques in Synthetic Fuels Analysis , C. W. Wright, W. C. Weiner, and

W. D. Felix, eds., Technical Information Center, U.S. Department of

Energy, 381-404 (1983).

Taylor,, J. K., "Reference Materials - What They Are and How They Should be

Used," J. Testing and Evaluation 11, 355-7 (1983).

Becker, D. A., "Proceedings, Measurements and Standards for Recycled Cil - IV", NES S.P. 674, U.S. Dept, of Commerce, National 3ureau of Standards,

Gaithersburg, MD 20899 (1984).

Becker, D. A., "Analysis for PCBs in Oil: The ASTM/N3S Round Robin", in

Proceedings, Measurements and Standards for Recycled Oil - IV, NBS S.P.

674, U.S. Dept, of Commerce, National Bureau of Standards, Gaithersburg

,

MD 20899' (1984)

Becker, D. A. and Hsu, S., "NBS Provisional Tests for Re-refined Engine Cil",

in Proceedings, Measurements and Standards for Recycled Oil - IV, N'BS S. P. 674, U.S. Dept, of Commerce, National Bureau of Standards,

Gaithersburg, MD 20899 (1984).

Becker, D. A., "The ASTM/N3S Basestock Consistency Study", in Proceed: rgs

,

Measurements and Standards for Recycled Oil - IV, NBS S.P. 67^, U.S.

Dept, of Commerce, National Bureau of Standards, Gai thersburg , MD —

(1984).

Hertz, H. S., "SRM* s and Definitive Methods: What are Their Roles in

Accurate Clinical Measurements?", Pathologist XXXXVIII 51,

(1984).

"

3

(0

4-)
May, W. E., Chesler, S. N., Hilpert, L.R., Hertz, H. S. , Rebbert, R. E. Vogt,

C. R. and Wise, S. A., "Characterization of Polycylic Aromatic Hydrocarbons in Air Particulate Extracts by Liquid and Gas Chromatographic

Methods", in Identification and Analysis of Organic Pollutants in Air, L.

R. Keith, ed., Butterworth Publications, Woburn, MA, 197-229 (1984).

Taylor, J. K., "The Rising Interest in Quality Assurance", TRAC 3, No. 4, 2-6

( 1984).

Taylor, J. K., "Limits of Detection", Anal. Chem. 56, 1 30A (1984).

Taylor, J. K., B. Kratochvil, and D. Wallace, "Sampling for Chemical

Analysis", Anal. Chem. 5(3, 113R-129R April ( 1984).

Taylor, J. K., "Guidelines for Evaluating the Blank Correction, "Testing and

Evaluation _1_2> 54-55 ( 1984).

Taylor, J. K., "Essential Features of a Laboratory Quality Assurance

Program," Statistics in the Environmental Sciences, ASTM STP845, pp

66-73 (1984).

Taylor, J. K., "What is Quality Assurance?", in Proceedings of Conference on Quality Assurance of Environmental Monitoring", ASTM STP 867 ( 1 984).

Welch, M. J., Cohen, A., Hertz, H. S. , Ruegg, F. C., Schaffer, R. , Sniegoski,

L. T., and White, V. E., "Determination of Serum Urea by Isotope Dilution

Mass Spectrometry as a Candidate Definitive Method", Anal. Chem. 56., 71 3-71 9 (1 984).

Becker, D. A., and Hsu, S., "The NBS Recycled Oil Program: 1976 to 1983" t in

Proceedings, Fifth International Conference on Used Oil Recovery and

Reuse, publ . by Association of Petroleum Re-refiners, Washington, DC

20006 (in press) .

Becker, D. A., "Quality Assurance Techniques for Activation Analysis," in

Proceedings, Fifth International Conference on Nuclear Methods in

Environmental and Energy Research, U.S. Dept, of Energy, Report XXX,

Washington, DC 20585 (in press).

Hertz, H.S., Wolf, W. R. , "Open Discussion On Needs and Uses for Biological

Reference Materials", in Biological Reference Materials Availability , Uses, and Need for Validation of Nutrient Measurement , W. R. Wolf, ed.,

John Wiley and Sons, Inc. New York, NY (in press).

Velapoldi, R. A., Hertz, "H. S. , "The Bases for Quality Assurance of Chemical

Measurements and Standards for Speciation" , Dahlem Konferenzen, Proceedings of Workshop on the Importance of Chemical Speciation In Environmental Processes, Berlin, Federal Republic of Germany, 1 984 (in press).

Taylor, J. K., "Quality Assurance of a Measurement Program," (to be published

in an ACS Monograph on Environmental Sampling)

Taylor, J. K., "Validation of Analytical Data", (to be published in Marine

Chemistry)

4
b. Talks

Becker, D. A., "The NBS Recycled Oil Program: 1 976 to 1983", at Fifth

International Conference on Used Oil Recovery and Reuse, November 14,

1 983, Las Vegas, Nevada.

Becker, D. A., "Analysis for PCBs in Used and Lubricating Oils", Las Vegas,

Nevada, November 16, 1983.

Hertz, H. S. , "Specimen Banking, Quality Assurance and Reference Materials

(Their Interrelationships and Roles in Monitoring Programs)", National

Bureau of Standards, Gaithersburg , MD , September 21 , 1983.

Hertz, H. S., "Role and Needs in Biological Reference Materials and Reference

Method", Federation of Analytical Chemistry and Spectroscopy Societies,

Philadelphia, PA, September 27, 1983.

Hertz, H. S. , "Interpretation of Mass Spectra" , ADABSE Workshop, November

1 983.

Taylor, J. K., "Quality Assurance of Chemical Measurements", ACS Short

Course, Eastman Kodak Co, Rochester, New York, October 1983.

Taylor, J. K., "Principles of Quality Assurance", Western Carolina Section,

ACS, Clemson University, Clemson, SC, November 1983.

Taylor, J. K., "Principles of Quality Assurance", Northeast Georgia Section,

ACS, University of Georgia, Athens, GA, November 1983.

Taylor, J. K., "Principles of Quality Assurance", Georgia Section, ACS, Agnes

Scott College, Atlanta, GA, November 1983.

Taylor, J. K., "Principles of Quality Assurance", Wilson Dam Section, ACS,

Florence, AL, November 1983.

Taylor, J. K., "Principles of Quality Assurance", Mississippi Section, ACS,

Mississippi State University, Starkeville, MI, November 1983.

Taylor, J. .K., "Quality Assurance of Chemical Measurements", ACS Short

Course, Houston, TX, November 1983.

Velapoldi, R. A., Organized Molecular Spectrometry Session and gave lecture

"Ultraviolet-visible and Luminescence Spectroscopy" , ADABSE Workshop,

November 1983.

Becker, D. A., "Quality Assurance Techniques for Activation Analysis", Fifth

International Conference on Nuclear Methods in Environmental and Energy

Research, April 4, 1984, Mayaguez, Puerto Rico.

Hertz, H. S. , "Ultratrace Organic Analysis", AFTACTND , Patrick Air Force

Base, Florida, January 10 , 1984 .

Hertz, H. S. , "Clinical Chemistry at the National 3ureau of Stand -.'' dr "

, Health Industry Manufacturers Association, Washington, DC, Januar. 1 1

, 1984 .

5
Hertz, H. S. , "Chemical Measurements for Industrial Applications of

Biotechnology", Eastman Kodak Company, Rochester, NY, June 29, 1984.

Hertz, H. S. , "Recent Applications of Isotope Dilution Mass Spectrometry"

,

American Association for Clinical Chemistry, Washington, DC, August 3,

1984.

Hertz, H. S. , "Ten Years of Chemical Analysis: A Decade to Trace",

Federation of Analytical Chemimstry and Spectroscopy, Philadelphia, PA,

September 17, 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", NBS sponsored

Short Course, Clark County Sanitation District, Las Vegas, NV, January

1 984.

Taylor, J. K., "Quality Assurance of a Measurement Program", EPA Symposium on Environmental Sampling, Las Vegas, NV, February 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", ACS Short

Course, Nalco Chemical Co., Chicago, IL, February 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", ACS Short

Course, Pittsburg Conference, Atlantic City, New Jersey, March 1984.

Taylor, J. K., "Statistics for Chemists", Pittsburgh Conference, Atlantic

City, New Jersy, March 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements" , NBS sponsored

Short Course, U. S. Geological Survey, Menlo Park, CA, March 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", ACS Short

Course, St. Louis, MO, April 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", NBS-UNIDO

sponsored training course, Shanghai Institute for Testing Technology,

Shanghai, China, April, 1984.

Taylor, J. K., "On Validation of Analytical Data", VIII International

Conference on Chemistry of the Mediterranean Sea, Primosten, Yugoslavia,

May 1 984..

Taylor, J. K., "Quality Assurance of Chemical Measurements", NBS Short

Course, NBS, May 1984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", NBS Short

Course, May 1984.

Taylor, J. K., "The Use of Control Charts in Analytical Chemistry", Ruder

Boskovic Institute, Zagreb, Yugoslavia, May 1 984.

Taylor, J. K., "Quality Assurance of Chemical Measurements", NBS sponsored

Short Course, EPA-EMSL, Cincinnati, OH, June 1 984.

Taylor, J. K., "Data Quality - What QA is All About", Keynote Address,

Johnson Conference of ASTM Committee D-22, Johnson, VT, July 1984.

6
Velapoldi , R. A., "The Center for Analytical Chemistry: Chemical

Compositional Measurements of Materials", Department of Defense - JDL

Technical Initiatives Panel on Advanced Materials, National Bureau of

Standards, Gaithersburg , April 18, 198*1.

Velapoldi, R. A., "Trends/Requirements in Analytical Chemistry", Doe - Health

and Environmental Research (OHER) Workshop on Chemical Measurement Needs

in Energy-Related Health and Environmental Research, Battelle-Seattle

Conference Center, Seattle, WA, May 14 -16, 1984.

Velapoldi, R. A., "Microspectrof luorimetry : Standards and Measurements",

University of Leiden, Leiden, The Netherlands, June 28 - 29, 1984.

Velapoldi, R. A., "Quality Assurance in Chemical Measurements", Dahlem

Konferenzen, Workshop on The Importance of Chemical Speciation In

Environmental Processes, Berlin, Federal Republic of Germany, September 1 - 8,1984.

c . Committee Assignments

Harry S. Hertz

Secretary, American Society for Mass Spectrometry

Member, ASTM, Committee D1 9 on Water

Member, CEQ, Interagency Task Force on Environmental Data and

Monitoring Air Pollution Data and Monitoring Working Group, Task Group in

Anticipatory Monitoring

President-Elect, NCCLS

Technical Advisor, OIML, SP26, Subcommittee SR5 on Reference Materials

for Calibration of Instruments Meant for Checking

Substances During Medico-Biological and Research Analyses

Member, Analytical Laboratory Managers' Association

Member, Department of Energy Health and Environmental

Research Advisory Committee

Ranee A. Velapoldi

Member, Interagency Toxic Substances Data Committee

Working Advisor, ASTM, Committee E7 on Nondestructive Testing,

Subcommittee E7.03 on Liquid Penetrant and MPI Methods, Task Group

E7.03.03 on E-270 Glossary Revision

Member , 'ASTM, Committee El 3 on Molecular Spectroscopy, Subcommittee

El 3.06 on Molecular Luminescence

Task Group El 3.06.01 on Presentation of Corrected

Fluorescence Spectra

Task Group El 3.06.02 on Recommended Practices on Molecular

Fluorescence Spectroscopy

John K. Taylor

Member, ISO/TC48, Glassware and Related Apparatus

IS0/TC48/SC01 , Volumetric Glassware

ISO/TC146, Air Quality

IS0/TC01 , Stationary Source Emission

IS0/TC02, Work Place Atmospheres

IS0/TC03, Ambient Atmospheres

ISO/TC04, General Aspects

7
Chairman, ASTM D19.01, International Standards

ASTM D22, Sampling and Analysis of Atmospheres

Member, ASTM D19, Water

ASTM D19.02, General Specifications and Technical

Resources

ASTM D19.05, Inorganic Constituents in Water

ASTM D19.07, Sediments

ASTM D22.01 , Quality Control

ASTM D22.02, Source Measurements

ASTM D22.03, Ambient Measurements

ASTM D22.04, Analysis of Work Space Atmospheres

ASTM D22.09, ISO TAG for ISO/TCI 46

ASTM, E34, Occupational Safety and Health

ASTM, E36, Criteria For the Evaluation of Testing and/or

Inspection Agencies

ASTM, E36.10, Generic Criteria

ASTM, E36.30, Nomenclature and Definitions

ASTM, E41 , Laboratory Apparatus

ASTM, E41.01, Glass and Plastic Apparatus

ASTM, E41.06, Weighing Devices

ASTM, E41.07, Microchemical Apparatus

Collaborative Testing Subcommittee - Standard Methods

Advisory Committee - CHEMTECH (ACS)

ACS Committee on Environmental Chemistry - Subcommittee on Environmental Analytical Chemistry

NBS Museum Committee

NBS Performance Review Board, SES

NBS Representative - Interagency Advisory Committee on Water Data

Donald A. Becker

Member, ASTM, Committee D-2, Petroleum Products and Lubricants

Subcommittees B, C, E, L, N, and PA. Publications

a. Other

a. Conferences

H. S. Hertz and R. A. Osteryoung, Chairmen, 37th Annual ACS Summer Symposium

on Analytical Chemistry, "Trends and Accomplishments in Electroanalytical

Chemistry," National Bureau of Standards, Gai thersburg , MD , June 11 — 1-4, 1984.

e. Center Colloquium Series

November 2, 1983 ' ~ Professor Raymond E. Dessy, Department of

Chemistry, Virginia Polytechnical Institute,

Blacksburg, VA, "The Rational Electronic

Laboratory" .

January 12, 1984 - Dr. Gunther Knapp, Institute for Analytical,

Micro- and Radiochemistry, Technical

University of Graz, Graz, Austria, "Some New

Techniques for the Decomposition of Organic

Materials in Trace Element Analyses".

8
January 18, 1 98 ^4 Dr. M. James Blackman, Conservation

Analytical Laboratory, Museum Support Center,

Smithsonian Institution, Washington, D.C.,

"Smithsonian Institution- NBS Cooperative

Programs”

February 8, 1984 Professor Stanley N. Deming, Chemistry

Department, University of Houston, Houston,

TX, "Optimization in Chemistry".

March 14, 1984 Dr. Norman Anderson, Argonne National

Laboratory, Argonne, IL, "The Human Protein

Index: Scope, Technology, Standardization

and Data Base".

August 27, 1984 Professor Nicolo Omenetto, CCR, European

Community Center (Euratom Joint Research

Center), Stabilimento di Ispra, "Analytical

Laser Spectroscopy at the Joint Research

Center of Ispra, Italy".

9
B. Voluntary Standardization and Quality Assurance

1. Voluntary Standardization

The Center continues to play an important role in standardization

activities. Thirty-five members of the staff hold 137 memberships on standards committees, including positions of leaderships on 9 of these, as follows:

ASTM C-26

ASTM D-1

ASTM D-22

ASTM E-02

ASTM E-07

ISO /TCI 46

ISO/TCI 117 IUPAC

NCCLS

Nuclear Fuel Cycle

Water

Sampling and Analysis of Atmospheres

Emission Spectroscopy

Nondestructive Testing

Air Quality

Water Quality

Commission on Atomic Weights

National Committee for Clinical Laboratory Standards

ASTM Awards of Merit were presented to John A. Norris (551) and to

John K. Taylor (550) in recognition of their contributions to the advancement

of voluntary standardization.

2. Quality Assurance

The Center's program to provide quality assurance education and

assistance to other government agencies and to the public has been very

active during the past year. A key feature of this is the Quality Assurance

Seminar series initiated in 1983. These seminars are of two types: those

held at NBS consist of 10 hours of lectures and 4 hours of small-group

discussions (mini-workshops) in selected measurement areas; those presented

away from NBS consist entirely of 16 hours of lectures given during a two-day

period. Essentially the same material is presented in the lectures of both

seminars, except that the content is enlarged in the case of the latter type.

Seminars of the first type were persented three times at NBS during the

past year to a total of 140 persons, largely from various industrial organizations. Three of the second type were presented to other government

agencies with a total attendance of 95 persons. The latter has also been

presented six times as an ACS short course to a total of 196 persons. This

swells the total to 1627 persons who have attended one of these seminars

since the series was started.

The seminar was presented at the Shanghai Institute for Testing

Technology (SITT), Peoples Republic of China, during a 3 week period in April

1984, under UNIDO sponsorship. Eighteen half-day sessions were needed to cover the material, consisting of sequential translation from English to

Chinese. Some 57 persons from 22 different technical institutes in the

Shanghai area attended. In addition, a half-day overview of modern quality

assurance was presented to 158 members of the Shanghai Association for

Science and Technology. The lectures in the series were taped and are being

translated for publication in the Chinese language, by SITT. In addition to

the above, a general lecture on quality assurance has been presented five

times during the past year to a total of 425 persons.

10
Two additional routes for extending the quality assurance influence of

the Center have been undertaken during the past year. One of these consists

in the preparation of a "Handbook for SRM Users" which discusses the philosophy of quality control of the measurement process and of the use of SRM's

for quality assessment of the measurements. Both general and practical

information is presented in the handbook which will be published within the

year as an NBS 260 series publication.

A generic quality assurance guidance document, "Principles of Quality

Assurance," has been prepared, under NOAA sponsorship, for use in the

National Marine Pollution Program (NMPP). The document will be initially

distributed at a NOAA-sponsored workshop to be held at NBS in December 1 984,

in which the several government agencies involved in the NMPP will participate. Although prepared for the NMPP, the document, due to its generic

nature, should be useful to most laboratories developing a quality assurance

program for specific measurement problems.

Closely related to the above, a "Quality Assurance Handbook for State

Weights and Measures Laboratories," has been prepared under sponsorship of

the NBS Office of Weights and Measures. This handbook contains 15 standard

operating procedures for the calibrations made most frequently by these

laboratories together with a collection of good laboratory practices and good

measurement practices related to them. Additional information contained

includes statistical techniques for data evaluation and discussions of

control charts. The handbook is expected to be ready for distribution by the

end of 1984.

John K. Taylor
c. Service Analyses

Service analyses are an important function of the Center for Analytical

Chemistry (CAC). Within the scope of this activity, the technical staff

gives advice, performs accurate chemical analyses, and provides state-of-theart calibrations on a wide range of research and standards materials. This

service is available, on request, to NBS staff and to all Federal, State, and

Local government groups. It is also available for use by the private sector

in those special instances for which CAC possesses a unique measurement

capability. Within the latter category, the two most frequent types of

requests are for the recalibration of SRM gas mixtures and for the verification of spectrophotometric transmittance SRM's.

In the performance of the service analysis function, every member of

the CAC staff is dedicated to providing timely, cost effective, and informative analyses. The turnaround time for the more straight-forward analyses

ranges typically from several days to about two weeks. All work is performed

on a cost reimbursable basis. Within NBS, funds are obligated on an interdivision work order and designated cost centers are cross-charged . All

outside work is performed on a purchase order.

During the first 11 months of FYS^, CAC staff provided analyses or recalibrations for some 98 requests at a cost of $273,800. These requests

and their associated funding were divided among the three categories of

customers as follows: NBS - 17 jobs ($36,700); other government agencies -26

jobs ($150,900); and private industry - 55 jobs ($86,200).

R . W . Bur ke

12
II. Inorganic Analytical Research Division

James R. DeVoe, Chief

Barry I. Diamondstone, Deputy Chief

A. Division Overview

The Inorganic Analytical Research Division conducts research that is

directed toward improving the accuracy of compositional measurements of

inorganic constituents in a variety of materials. This research takes the

form of basic studies on new principles of chemical analysis as well as improvements to existing methods. In addition, the Division uses accurate

methods to certify Standard Reference Materials, to provide analytical

services for other government agencies, and to provide analytical support for

solving problems related to national needs. The Division is organized into

five groups which are oriented to specific technical disciplines. The groups

are: Activation Analysis, Analytical Mass Spectrometry, Atomic and Molecular

Spectrometry, Electroanalyti cal Chemistry, and Laser Analytical Chemistry

which was transferred from the Center Office during this past year.

The Division strives to maintain a satisfactory balance between

research and development of analytical methods and analysis of materials such

as SRM’s that serve as critical analytical tiepoints to accuracy. At

present, considerable effort on research is needed to provide the capability

necessary to keep up with the latest developments in high accuracy analytical

measur ements . Too often in the past our need to concentrate on problems with

the analysis of specific materials has diverted attention from maintaining

our state-of-the-art capability. Nevertheless, we have made significant

progress in our research program.

The study of laser photoionization processes has resulted in significantly improved ionization efficiencies for a number of elements. As a result, a new series of elements may be determined by isotope dilution mass

spectrometry. The neutron depth profiling (NDP) technique continues to

increase capability, particularly with respect to depth resolution which is

of crucial importance to the solid state electronics industry. This project

is drawing the attention of a number of materials scientists both from

industry and universities (Technical Report 2, page 24) . Many of the current

manufacturers of solid state (silicon) devices are working with us to

evaluate the technique. Another major accomplishment is that relative

standard deviations approaching 0.5? have been attained with precise gammaray counting. This opens up major new opportunities for activation analysis

including the determination of macroconstituents in SRM’s and the measurement

of isotope ratios which has application in a variety of tracer studies as well as the Division's atomic weight program.

The need for the accurate measurement of acidity, as related to the

measurement of acid rain, generates controversy regarding the convention of

using pH as the indicator. Since the term relates to the thermodynamic

activity and not hydrogen ion concentration, the necessity for evaluating

ionic strength and liquid junction potential when electrochemical measurements are made, requires that standards be used that approximate (rath*-”

closely) the "real" samples that are to be measured. The leaching property

of acid rain probably relate to hydrogen ion activity rather than concert- - tion; therefore, studies to eliminate the systematic errors due to sam;'.

13
type are very important. Using diluted strong acids as standards will help

with part of the problem and some recent ideas on the reduction of the liquid

junction potential must be pursued (see Technical Report 19, page 38).

Often neglected research components of the analytical process are chemical dissolution, blank reduction, and chemical separation. There are a number of advances in technology which allow energy to be selectively added

to the sample so as to minimize losses of sample constituents during the

dissolution step and thereby improve the accuracy of the analysis. In

addition, the recent trend is to do as little chemical separation of the

elements as possible, and to rely on the instrumental methods for eliminating

interferences. While in some cases such reliance appears to be well founded,

in others, the appearance of errors due to interference resulting from

incomplete instrumental selectivity is well documented. While chemical

separation procedures are labor intensive, it is important that we continue

to study this area, and although we analyze a variety of sample types

throughout the year which makes automation difficult, it may still be

possible to automate some of the separation and dissolution steps.

Particularly noteworthy is the work of three of our staff members who

received IR-100 Awards from the publication, Industrial Research. (See

Technical Report 18, page 37 discussing the use of the vibrating electrode in

voltammetry and Technical Report 20, page 39 discussing the use of sulfur

isotopic tracers in the environment.) These are the first such awards in the

Division and we are very proud of these accomplishments.

A large number of samples have been analyzed this year as part of our extensive contribution to the SRM program (Technical Report 21 , page ^0)

along with the service analyses which we routinely perform. The distribution

of effort in the certification process among the groups in the division is

somewhat non-uniform. A program is in place to correct this situation. In

addition, a great deal of effort has been invested in analyzing samples from

Other Agencies. Many of these samples relate to the "calibration" of

agency-made standards to be used as quality assurance materials for their own laboratories. In the future, we will continue attempts to assist such

agencies in the formulation, design, and generation of these materials so as to improve the overall utility of their quality assurance programs and

provide materials with traceability to CAC.

During this past year, the Division has substantially increased its

interactions with other scientists in industry, other government agencies and

universities both in this country and abroad. This has resulted in a significant number of guest workers who have joined the various groups in the

Division for periods of time ranging from a few months to two years. The

sharing of ideas has proven beneficial to both of us.

Future plans involve combining an in-depth understanding of the

systematic and random errors present in the analytical methods routinely used

in the Division with as much automation, robotics, and computer control as possible without compromising the analytical accuracy. This would lead to a significant increase in the effectiveness of the Standard Reference Material

program. In addition to improving the accuracy of the certification -measure- ments , throughput will be increased, and a wider variety of sample types will

be certified.
1 . Activation Analysis Group: Overview

The development and application of nuclear analytical techniques for

greater accuracy, higher sensitivity and better selectivity are the goals of

the Activation Analysis Group. A high level of competence has been developed

in reactor-based activation analysis, which includes instrumental and

radiochemical neutron activation analysis (INAA and RNAA) , and in LINAC-based

activation analysis using photons (PAA). In addition, the group has a unique

capability in neutron beam analysis with both prompt gamma activation

analysis (PGAA) and neutron depth profiling (NDP). The NDP technique

utilizes prompt charged particle emission to determine elemental distributions within the first few micrometers of a surface while the PGAA technique

utilizes prompt gamma-ray emission to measure the total amount of an element

regardless of its location in the sample. These techniques provide an arsenal of tools to address a wide variety of analytical problems in science

and technology.

During the past year, research efforts in INAA have been directed

toward extending its multielement capability by investigating short-lived

activation products (T-j /2 * 1 s) and epi-thermal activation analysis using

shielded irradiations . The work with RNAA has continued to expand the number

of elements which can be quantified at or near the theoretical detection

limit of the method. Especially challenging have been gas-phase radiochemical separations which have allowed routine measurement of 129i at the

108 atoms per gram level. Work on the certification of U-235 standards has

demonstrated that a precision well below 0.1$ can be achieved with gamma-ray

spectrometry . Since random counting uncertainty is the ultimate limitation

on the accuracy of all activation measurements, the challenge now exists to

understand and, where possible, reduce systematic errors to below the 0. 1 ? level

During the past year, there has been a continuing effort in the area of

trace element analysis of biological materials. In addition to the ongoing

work on biological Standard Reference Materials and the Pilot Environmental

Speciman Book program, several new research areas have been established.

Activation analysis is being used to study the interrelationships among trace

elements, bioanalytical separations, and biological macromolecules. Cf

particular interest is a beginning effort employing a chromium isotope

dilution technique to measure the increase in total blood volume during

pregnancy.

With the success of the Bureau's initial effort to establish a National

Facility for Cold Neutron Research at the NBS Reactor (N3SR), both of tr.e Group's neutron beam techniques, PGAA and NDP, have the potential of improving in sensitivity and throughput by at least a factor of one hundred. The

increased neutron intensity and reduced background will allow, for example

depth profiling of nitrogen and chlorine by NDP and the prompt gamma determination of hydrogen and boron at the ng/g levels. This will give the Buret ; an unprecedented ability for chemical compositional analysis of materiel

such as metals, glasses, and semiconductors as well as more complex mat

The coming year will see an upgrade of the NBSR from its present ’ power level to the full design power of 20 MW. This will provide a fa< * • two improvement in many of our activation analysis sensitivities art . r. of our PGAA and NDP analyses. While this upgrade is taking plae~, -

15
install a new data acquisition system based on a VAX computer to replace the

outgrown 1 6-bit system now in use. In addition to the control and processing

of gamma ray spectra now carried out, the enhanced computational capability

will be used for substantially improving the modeling of the activation

analysis process to improve its accuracy.

Ronald F. Fleming, Group Leader; M. James Blackman, B. Stephen Carpenter,

R. Greg Downing, Kathleen A. Fitzpatrick, Robert R. Greenberg, G. Yenkatesh

Iyengar, John K. Langland, Richard M. Lindstrom, George J. Lutz, John T.

Maki, Susan F. Stone, Rolf L. Zeisler

2. Analytical Mass Spectrometry Group: Overview

The Analytical Mass Spectrometry Group develops and maintains the

capabilities required to perform compositional measurements using the

analytical sciences of chemical separation and mass spectrometry. For many

years, the Group has been involved in chemical separations, plus the highly

precise and accurate isotope ratio measurements required to determine the

atomic weights of the elements and to make very definite measurements of

trace element concentrations. While maintaining the basic thrust in the

traditional areas, the horizons of the Group have broadened markedly in the

past few years. Predicated on the competence building program and related

basic research, substantial changes have been initiated to develop new capabilities for chemical separations and ion spectroscopy. By combining the

foundation evolved from many years of measurement research and applications

with the recently initiated fundamental changes described below, we anticipate that a new generation of measurement capabilities for analytical mass spectrometry and compositional analysis will be achieved.

Research in the ion mechanisms competence building program has resulted

in several significant accomplishments during the past year: resonance

ionization mass spectrometry (RIMS) has been used to extend the demonstration

of ionization feasibility to twenty-eight elements; a systems calibration

using 57Fe/56pe ratios has been completed for the RIMS system; the RIMS

system has also been used for isotope dilution analysis of iron in SRM’s;

auto-ionization levels and the spectroscopy of previously unobserved Rydberg

structures have been studied for beryllium in collaboration with personnel

from the Center for Radiation Research; the systematics have been explored

for multielement analysis, and seven elements in a mixture have been selectively ionized. Research has also been initiated to study thermal molecular

positive ion formation that will lead to the determination of isotope ratios

and elemental concentrations by isotope dilution for elements such as Se and

Te.

Several of the Group’s technical outputs have been highlighted in the

following Technical Reports. Not included are a number of other areas that

contribute substantially to the overall output and technical support. The

RIMS laboratory has been expanded and equipment installed to initiate an all-new narrow bandwidth, high sensitivity RIMS system; isotope dilution

procedures have been developed to determine ultra-trace levels of vanadium in

biological materials; the gaussmeter-controller on the mass spectrometers

have been modified to permit digital control; and the first prototype of a new electrometer has been completed to replace commercially unavailable

components. The NBS-Smi thsonian collaboration has continued for the use of

lead isotope ratios in the provenance determination of archaeological

16
artifacts, with much of the activity focusing on Chinese artifacts. In

addition to these activities and projects, members of the Group have carried

a substantial load of SRM certification work, and have provided quality

services for Other Agencies, ranging from consultation, to high precision

isotope ratio measurement, to designing and building instrumentation and

electronics

A substantial contract has been negotiated with a major chemical

manufacturer to utilize the Division’s unique trace element measurement capabilities to examine the purity of fluorocarbon polymers. This project

reflects a synergistic interest in the reduction of impurities in state-ofthe-art containers, reagents and materials.

Plans for next year include investigations of the analytical capabilities of inductively coupled plasma mass spectrometry, (ICP-MS). The ICP-MS

system also will be evaluated for its applicability to isotope dilution

analysis, and mechanisms of material transport to the spectrometer will be

investigated. A collaborative effort with the Surface Science Division,

Center for Chemical Physics has been initiated to examine the sample transport and energy transfer mechanisms associated with the ion bombardment

sputtering of solids. For this purpose, time-of-flight RIMS will be used as an energy state-specific probe to examine the nature of the sputtered neutral

and ionic species, and to evaluate the resonance ionization pathways required

for the studies. Initial progress on the investigation of molecular ions

formed by thermal processes will continue in an attempt to understand the ion

formation process and to provide a basis for ultra-trace determinations of

selenium and tellurium by isotope dilution mass spectrometry. Research

efforts will also be initiated for the determination of the atomic weights of

lithium and nickel. As part of this effort, the importance of fringing field

effects will be assessed for lithium isotopic measurements. Substantial

progress is also anticipated in the ensuing year for the automation of

chemical separation procedures, and for the development of microwave dissolution technology. Research in these two areas - dissolution and separations - has progressed smoothly during the last year, and significant milestones

should be achieved during the next year. At the interface between the

competence building program and an other agency project, we will further

develop RIMS technology directed toward the measurement of small numbers of

an(j uranium atoms. Finally, we will continue to explore the potential of

stable isotope tracers in the environment. Through these efforts, and by the

maintenance of quality services to the OSRM and other agencies, we hope to

achieve a balanced program of growth in newer technical areas, while maintaining a solid and progressive foundation in the traditional areas of high

accuracy isotope dilution mass spectrometry.

We are most pleased ' to announce that Paul Paulsen and Bob Kelly have

been awarded one of the coveted and competitive IR-100 awards for their

research on sulfur isotopic measurements (see Technical Report 20, page 2- . Dr. Heinz Zeininger from the laboratory of Prof. Klaus Heumann has joined cur group for a one year stay as a foreign guest worker from the University cf

Regensburg, Regensburg, Germany. Dr. Zeininger will interact principally ;• the research areas of RIMS and negative thermal ionization mass spectre:-- ‘

• y .

L. J. Moore, Group Leader; I. L. Barnes, E. S. Beary, W. A. Bowman, III,

K. A. Brletic, E. C. Deal, J. D. Fassett, J. W. Gramlich, S. A. Hotes,

L. B. Jassie, W. R. Kelly, H. M. Kingston, G. M. Lambert, L. A. Mach! ,

17
J. R. Moody, T. J. Murphy, P. J. Paulsen, L. J. Powell, D. W. Schwartzman,

R. W. Shideler, R. J. Zeininger.

3. Atomic and Molecular Spectrometry Group: Overview

The principal objectives of the Atomic and Molecular Spectrometry Group

are to conduct research in the fundamental processes in spectrochemical

analysis and to apply the results of this research to compositional measurement problems and the characterization of Standard Reference Materials. This

research involves the study of basic processes in chemistry and physics and

is directed toward improving the precision and accuracy of the methodology.

During the past year, the major activity of the Group has been in

characterizing Standard Reference Materials (SRM's), participating in

programs of national concern, providing service analyses on highly complex

samples for other government agencies and industry as well as other divisions

at NBS , and providing a training program for guest scientists. To accomplish

these activities, the following techniques were used extensively: atomic

absorption spectrometry (AAS); optical emission spectrometry (spark); inductively coupled plasma emission spectrometry (ICPES); direct current plasma

emission spectrometry (DOPES); gases in metals; and uv-vis spectrophotometry

Research on the mechanism of material transport is continuing. Results

from this study should play an important role in explaining the fundamental

processes in the spark discharge which affects the transport of bulk sample

to a measurable state. In addition, the feasibility of coupling the spark

discharge with other excitation sources such as an air-acetylene flame or a direct current plasma is under investigation. A cooperative effort with the

Laser Analytical Chemistry Group was initiated this year to couple various

analytical spectroscopic techniques with laser probes. Laser fluorescence in

flames and laser enhanced ionization in the ICP were studied to evaluate

sensitivity and interferences encountered in these techniques for trace

elemental analysis.

The Group is participating in a project for the development of luminescent glass spheres to serve as standards for calibrating microspectrof luor imeters used in quantitative immunofluorescence assay. Glass compositions

which produce both broad and narrow band emission spectra are being evaluated.

The work in the area of gases in metals has continued. Methods developed for the determination of carbon, sulfur and hydrogen have been utilized

to certify a number of new SRM's with improved precision and accuracy. These

techniques are now used also to carry-out the numerous homogeneity studies

routinely required in the metals program and for a variety of service

analyses

Optical emission spectrometry (spark) was used extensively in homogeneity studies of SRM's (aluminum alloys, irons, steels, brass-bronzes and

leads). The planning and monitoring of the production of an SRM Battery Lead

18
and a replacement low alloy steel are underway. An interesting project

involved the determination of chemical composition of flanges for photomultiplier tubes on a current satellite project for NASA. Cf the several alloys

tested, NASA determined that only one alloy was suitable as a flange material .

A major part of the overall group effort involved the characterizati

of 22 different SRM's for 75 major, minor, and/or trace elements by A AS , SC

IC? ar.d spectrophotometry. The materials characterized varied considerab

and included brick clay, coal, rutile, oil, urine, and botanicals.

determine 11 elements in the brick clay, three different dissoluti

procedures (two basic fusion and a wet oxidation method) were developed

prepare this refactory material for the final DC? and AAS measurements. A and IC? were used to determine 22 elements in the SRM Coal which requir

four separate dissolution procedures to prepare the material for fin

analysis. A comparison between Zeeman and deuterium arc methods for bac

ground correction of AAS was made during the characterization of lead

whole blood. The bleed-lead method oreviouslv develooed at NBS was used

on

p* » ly

To

on

to

kdemonstrate that the two methods were in good agreement. AAS with electrothermal atomization was used to determine trace elements in human liver, acid

rain, and germanium which is being clinically evaluated as an anti-neoplastic

agent on carcinoma cells and as an anti-malaria drug at Georgetown University

Hospital. Samples of serum, plasma, red blood cells, urine, and bile from

patients treated with the drug showed a marked decrease in germanium concentration with time. Additional tests are planned to determine the fate cf the

germanium.

An additional capability now exists for determining fluoride

and similar liquids in which the fluoride is present in ionic form,

procedure entails separation of fluoride from the sample matrix

collection by absorption in an alkaline solution, and determir.atio:

"lucride by spectrophotometry

stucy

m urine

The new

p q ur

9

i of the

separated different crrar.ic

solvents to improve the analytical accuracy of trace elemental ana

IC? was undertaken; however, no single solvent was found to be the

all elements. Consideration of signal-to-backgrour.d ratios as background structure near the analyte peak wavelength were four,

critical in choosing the best solvent for a particular element.

lysis by

best for

well as

a to be

Another significant investigation was the evaluation of AAS with

hydride generation and chelation-solvent extraction techniques fc- the

separation, preconcentration, and determination of total tin and tributyltir

from seawater. Tribulyltin oxide is extremely toxic and is used as an antifouling coating for ships' hulls. The toxic compound leaches from tn- coati.ng matrix which discourages settling forms of marine organisms. Plan.: are underway to continue this study and to expand it to the analysis cf se:

sediments and soft tissue.

In high accuracy spectrophotometry, significant prog-ess

in the production of SRM Glass Transmittance, Metai-on-Quar

Light Attenuation Filters. The wedge effect, reported last

been completely resolved, but work is continuing in this area

has beer, made

:z, and Stray

year, has not

Our initial

19

CO

TJ
work to extend the measuring capability of the NBS-CAC high accuracy spectrophotometer into the near-inf rared region of 0.8 to 2.4 pm was not accom- plished because of che inability of the vendor to deliver optical components.

As a result, a design for this extension into the near-inf rared has been

developed in house, and the system is under construction.

Research during the coming year will focus on several areas. In

material transport studies, techniques used to characterize the physical

properties and chemical composition of pure elements and brass alloys will be

extended to more complex materials. Also, the use of mobility particle

counts as an indicator of the amount of material sampled by the spark will be

investigated. Studies of flow injection sample introduction and ultrasonic

sample nebulization for DOPES and ICPES will continue. Accurate, discrete

microsample introduction is facilitated by the use of a rapid wavelengthmodulation background correction device in the echelle spectrometer of DOPES.

The continuous flow mode of the flow injection system permits automated

standard addition and sample buffering. The technique of ultrasonic sample

introduction has the potential of increasing the analytical sensitivity of

many analytes in ICPES and DOPES. The problem of sample memory encountered

with ultrasonic nebulization has been corrected with a new cell design. Plans

are underway to re-establish some of the classical techniques for gases-inmetal to check the accuracy of our present gases-in-metals instrumentation.

Methods to be utilized include the Kjeldahl method for nitrogen, the classical gravimetric and potentiometric methods for hydrogen and oxygen, and a 14

MeV nuclear activation technique for oxygen. Also, a study of various ways

to introduce samples into the inductively coupled plasma-mass spectrometer

should provide improvement of the sensitivity of this technique and

suppression of matrix interferences.

Theodore C. Rains, Group Leader; David E. Brown, Robert W. Burke, Therese A.

Butler, Barry I. Diamondstone , Michael S. Epstein, Radu Mavrodineanu , De-ming

Mo, John A. Norris, Theresa A. Rush, Joichi Ueda, Robert L. Watters, Jr.,

Yong-Kang Zhang.

4. Electroanaly tical Chemistry Group: Overview

The Electroanalytical Chemistry Group conducts basic research and

utilizes electrochemical principles to develop techniques and apply them to

chemical analyses. The techniques in practice include amperometry, conductimetry, coul'ometry, ion chromatography, polarography , potentiometry , and

voltammetry. Research activities are directed toward attaining a more thorough understanding of the complex electrochemical processes encountered

in the development and implementation of electroanalytical methods.

A major effort in the past year has involved the measurement of pH in

various matrices, for example in low ionic strength solutions, which is of

great utility for acid rain programs. It had been previously established in our laboratory that the residual liquid junction potential was the dominant source of error in such measurements. Research was conducted to develop

improved measurement procedures and to develop new pH calibration standards

which would minimize this error. The results of a round-robin exercise

indicate that matrix specific pH standards significantly improve the precision and accuracy of the measurement if a definite procedure is followed

explicitly. A ruggedness test of the procedure is now underway to determine

the degree of control necessary for each component of the procedure. A new

20
Research Material, RM 8 -409 Simulated Rainwater, has been developed to aid in

the analysis of rainwater. Work will continue on this project to develop a Standard Reference Material for rainwater. (See Technical Report 19, page

38).

Efforts in other aspects of pH measurement research continue with the

certification of a new lot of potassium acid phthalate for pH, SRM I85f (one

of the most widely used pH buffer materials) and the certification of two

materials for pD, potassium acid phthalate and sodium bicarbonate/sodium

carbonate. A more reliable procedure for preparing stable and reproducible

silver/silver chloride reference electrodes has been developed and fundamental studies of the standard potential of this electrochemical couple are in

progress. A collaborative effort in this endeavor has been initiated with

the Radiometer Corporation. Thermodynamic studies in deuterium oxide have

also been conducted. The use of a silver chloride membrane as an ionic

conductor instead of the conventional liquid junction barriers has teen

preliminarily tested. This effort will require considerable research, but

appears very promising.

Research in voltammetry has included the development of a flowinjection system using a vibrating wire electrode detector. The main

advantages of this system are improved sensitivity due to increased mass transport to the electrode and the ability to investigate hydrodynamic

modulation independent of sample flow-rate. Dr. Pratt received an IR-100

Award for this achievement. Diffusion processes at ultramicro wire electrodes have been studied, and the effects of surface roughening explored. A new method for the determination of Cr(VI) has been developed using vibrating

wire electrodes both in a conventional cell and in the flow-injection mode.

The electrode can be either gold or palladium. The method is free from

interference of chrominum in other valence states, iron and chloride. (See

Technical Report 18, page 37).

Advanced ion chromatography instrumentation has been acquired and will

be used to improve the determination of anions via better sensitivity and

selectivity. It will also be used to extend our capabilities to the determination of the alkali metals and ammonium, and ultimately, to the alkaline

earth and transition metals. The existing instrument has been used extensively this year in the analysis of SRM coals and oils, of rainwater audit

and research materials, and in research to develop a new method for the

determination of fluoride in biological materials.

Coulometry in the controlled current mode has been used for high

accuracy assays of the acidity of rainwater research materials, of the

acidity of HC1 and DC1 solutions used in pH and pD research, and for the

standardization of chloride solutions to be used as standards for activation

analysis. Rutile Ore (SRM 670) was analyzed for titanium content by con- trolled potential coulometry.

Research has been initiated to develop advanced expertise in aque

conductance measurements with the view towards issuing a SRM and t ~ •

. understanding the fundamental relationships among conductivity, i \.

mobility, diffusion, and ionic strength.

21
We continue to expand our resources and scope of research through

active use of the postdoctoral and guest worker programs and industrial and

academic collaborations. This year the group is composed of three permanent

research chemists, one postdoctoral research associate, a visiting university

faculty member, a guest worker from the People's Republic of China, and a summer student. In addition, Eva Deak from the National Office of Measures

of Hungary will be visiting for one month to exchange information on pH

measurement and research. The group maintains its involvement with ASTM and

NCCLS through active participation in meetings and task groups. Efforts are still underway to identify a research associate to develop methods and

reference materials for the potentiometric measurement of calcium in biological fluids.

Research in pH will continue as a long-term commitment to provide

reliable and thermodynamically significant measurements and standards in this

most widely used analytical parameter. The development of a series of

matrix-specific pH standards is a high priority. Investigations in aqueous

conductance will continue. Advancements in ion chromatography will be

explored, focusing on improved resolution and sensitivity. Flow-injection

analysis with electrochemical detection will be implemented for determinations of trace metals in complex matrices. Voltammetry will be re-established

as a valuable analytical research technique within the group. Determination

of metal species by valence and by complexation will be a dominant research

direction.

William F. Koch, Group Leader, Han Kai , Melissa Knoerdel, George Marinenko,

Kenneth W. Pratt, Jr., Rubye P. Torrey (visiting faculty), and Yung Chi Wu

5. Laser Analytical Chemistry Group - Overview

The objective of this group is to develop new concepts for performing

spectroscopic analysis. The major emphasis is in the use of lasers as spectroscopic probes and is centered about laser enhanced ionization (LEI),

resonance ionization mass spectrometry (RIMS), and laser infrared diode spectroscopy. No major shift in direction is anticipated as a result of the

group being transferred to the Inorganic Analytical Research Division.

A major review on the theory and development of the laser enhanced

ionization in flames (LEIF) was completed this year. This paper was reviewed

by Ph. Alkemade, a reknowned expert on the physics of analytical flames who

stimulated our interest in extending our studies of the ion formation

processes. In addition, calculations have been done on the time dependent

electric field, ion, and electron densities that now enable us to prepare a major paper on the theory of the ion collection process. Our attention is now turned toward the theory of ion formation by photoexcitation processes

both in LEIF and RIMS.

The analytical applications of LEIF are proceeding well. A major

contribution was the work for Shell Development Laboratory and Sohio

Research. (See Technical Report 7, page 28.) We also contributed to the

measurement of some standards to be used for the calibration of inductively

coupled plasmas for the EPA. The redesign of the apparatus has been delayed

by the unavailability of software which will be used to incorporate the

wavelength calibrator. However, progress has been made on automating the

remainder of the system. We expect to continue analyzing samples for OSRM

22
and Other Agencies. In addition, we have received support from the Office of

Standard Reference Materials to evaluate random and systematic errors in the

techni que .

A longstanding interest of this group is the generation of a new component of the atomic spectroscopic analytical system that can be identified as the sample transport-atom reservoir. If it can be ascertained that some type of device such as a spark or laser can transform material from the

sample into a vaporous state without compositional bias, then use of an atom

reservoir to contain the sample may result in an analytical system of very

high accuracy with few, if any, matrix effects. Initial efforts are involved in a collaborative study with the Atomic and Molecular Spectrometry

Group to determine whether material maintains integrity during the vaporcondensation process when transported. Results to date for the spark

indicate a possible bias for a brass sample (see Technical Report 7, page 28

for more detail). We will develop more efficient procedures for collecting

the aerosol that is produced and also we will investigate the potential of

laser ablation for aerosol production.

Well over half of the effort of this group involves collaboration with

other scientists in the Division, Center, and Bureau (several of these are described in other Technical Reports). In the Division — Mass Spectrometry

Group on RIMS and on Automation of Group Separations of the Elements; Atomic

and Molecular Spectrometry Group on Spark Material Transport and Aerosol

Characterization; Organic Analytical Research Division — Mass Spectrometry

Group on Laser Photofragmentation; and the Gas and Particulate Science

Division — Microanalysis Research Group on Material Transport Particle

Analysis, Gas Metrology Group on the Analysis of Nitrous Oxide with the Ir

Diode Laser and the design of a thermostated gas cell for freon analysis; the

Atmospheric Chemistry Research Group on the HO2 Radical and HC1; and the

Center for Radiation Research, Instrumentation Group on the Design of a Spark

Generator. We also have a major effort in laboratory automation both for the

Group and others. A member of our Group chairs the N3S microprocessor

storeroom committee and provides a significant service to the NML staff on matters pertaining to the NBS storeroom microprocessor system.

James R. DeVoe, Group Leader, Fillmer C. Ruegg, Robert L. Sams, John C.

Travis, and Gregory C. Turk

23
B. Selected Technical Reports

(Inorganic Analytical Research Division)

1 . Determination of Boron in Borosilicate Glasses by Neutron Capture

Gamma-Ray Activation Analysis (15310) ~

R. M. Lindstrcm and J. E. Riley, Jr. (AT&T Bell Laboratori es

)

Optical waveguides are rapidly assuming a major place as media in data

and voice communication. As part of a study of micrometer-scale spatial

gradients in the composition of waveguide glasses, neutron capture prompt

gamma-ray activation analysis has been used to determine the boron contents

of seven borosilicate glass materials, ranging from 1? to 8? boron. This

instrumental method does not require the dissolution of sample, which may be

difficult to achieve for these materials.

A series of glasses was obtained frcm Corning Glass Works. The

supplier provided information about nominal batch compositions, to within

20?, which was used to select the experimental parameters. Neutron self

shielding can lead to substantial bias in these high-boron materials. The

effect was minimized by diluting the powdered samples with high-purity

graphite and by performing comparative analyses with SRM 93a Glass, diluted

in a similar manner, as a standard in addition to the primary standard

prepared from SRM 951 Boric Acid.

Measurements of the graphite and of pure quartz processed in the same way as the samples showed a blank of less than 150 ng B/g. When duplicate

mixtures of glass and graphite and replicate portions of the same mixture

were analyzed, the results showed that the samples were prepared with better

than 1? reproducibility and homogeneity. Comparative analyses of the same materials by ICP-OES gave excellent agreement, the mean ratio between the two

techniques being 1.00, with a relative standard deviation of 2.5?.

2. Neutron Depth Profiling: Development and Intertechnique Comparisons

(15310)

R. G. Downing, J. T. Maki, and R. F. Fleming

During the past year, the technique of neutron depth profiling (NDP)

has been significantly advanced through research and development, and industrial interactions. This is evidenced by the seven manuscripts that have

either appeared or are in preparation for journal publication, most resulting

from interactions with outside users of the facility. At present, these interactions include two research associates, four guest workers and more than

ten other scientific collaborators from U.S. industries and universities.

Intertechnique studies formed a major thrust of this year’s efforts.

NDP was used as a reference technique between secondary ion mass spectrometry

(SIMS) and spreading resistance profiling (SRP) for studies of boron

implanted silicon wafers. Of particular importance was the ability of NDP to

give reliable measurements of dopant profiles across interfacial boundaries

of insulating and semiconductor materials. NDP is one of the f ew -techni ques

that can be used to quantify accurately boron concentrations and profiles in

insulating materials. In addition, NDP was used to referee an abundance

discrepancy between the Auger electron spectrometry value for the implanted

2*4
nitrogen concentration in a tooling die metal and the surface dose recorded

from the ion beam current of the implanter. This was the first time nitrogen

profiles have been measured by NDP in a U . S. facility.

Three salient improvements have been made over the last year: (1) The

background arising in the spectrum from neutron and gamma beam interactions

with the target chamber has been reduced by a factor of three through the

customizing of shielding components. This innovation has already been transferred to a collaborating NDP facility at the University of Michigan. (2)

Interactive computer software was developed to model implant profiles,

allowing NDP spectra to be deconvolved. The software has been particularly

useful in unfolding helium and nitrogen profiles in semiconductor and metal

samples. (3) It was demonstrated that by measurement of concentration

profiles at low grazing angles with respect to the sample surface the depth

resolution of NDP could be improved by more than a factor of three. Through

comparison with SIMS and this type of shallow angle NDP profiling, artifacts

arising at SiC^/Si interfaces in SIMS spectra are being studied and methods

are being developed to correct the SIMS profiles.

Future directions include developing NDP into a multidimensional

technique through the use of position sensitive detector systems and greater

efforts in spectral deconvolution. Of the many applications for twodimensional NDP, nondestructive lateral diffusion studies of dopants and

their concentration on the submicrcmeter scale offer immediate benefit to

semiconductor research. Also, investigations of grain boundary segregation

of mobile constituents in high-technology alloys would be of widespread

utility. Through these developments, NDP is becoming increasingly useful and

applicable as a research and development tool for industry and science.

3 . High Accuracy Determination of 235^ in Nondestructive Assay Standards

by Gamma-Ray Spectrometry (153101

B. S. Carpenter and R. R. Greenberg

High precision gamma-ray spectrometry measurements have been made on five sets of uranium isotope abundance Standard Reference Materials (SRM's)

for nondestructive assay (NDA). These sets, SRM 969, were prepared in a joint effort with the Commission of European Communities' Central Bureau of

Nuclear Measurements (CBNM) and are intended for international safeguards use

as primary reference materials for the determination of the 235jj abundance ir. homogeneous uranium material by gamma-ray spectrometry. The measurements

consisted of determining the counting rate uniformity of the 2 35y 185.7 keV

gamma rays as well as the 235u isotope abundance for each sample. Since the

samples were packaged so the U

3 O8 was infinitely thick for the 185. 7 keV

gamma ray, the measured counting rate was nearly independent of the material

density. In addition, the activity observed by the detector was collimated to

simulate calibration conditions used to measure bulk material in the field.

The isotope abundances for all five sets, as determined by gamma-rv/

spectrometry , agreed with the average of the thermal ionization mass spectrometry values to £0.1?. The measurement variations within the 5 s-ts r samples ranged between 0.05 - 0 . 11 $ (Is) with standard deviations of the r ranging from 0.01 - 0.02$. This observed variation appears to be due predominantly to counting statistics and not to material inhomogeneity -r : packaging

25
The results of this study indicate that accuracy of 235u determination

via gamma-ray spectrometry , in the range of few hundredths of a percent

(2 sigma), is achievable. The main requirement for achieving this level of

accuracy is a set of counting standards whose 235u isotope abundances are known to within 0.01$ (2 sigma).

4. Accurate Multi-Element Analysis of an Aquatic Accumulator (15310)

S. F. Stone, R. Zeisler and R. Sanders (Pacific Northwest

Laboratori es

)

A joint research program, involving the National Bureau of Standards

and the Environmental Protection Agency, has been concerned with the study of

biological specimens as monitors of the marine environment. Several analytical techniques were used to obtain concentrations for over MO elements in

selected specimens. Steps were taken to assure the accuracy of the reported

measurements by avoiding contamination not only in the chemical analyses, but

also during sampling and sample preparation. This was especially important

for elements occurring at trace levels.

The organism selected as the monitor for the marine environment was Mytilus edulis , a marine mussel. The mussels were collected under controlled

conditions, separated into batches, and stored. Before analysis, the mussels

were shucked and then cr yogeni cally homogenized. Three instrumental techniques were then applied sequentially for analysis; (1) backscatter with

fundamental parameter X-ray fluorescence (BFP-XRF), (2) neutron-capture,

prompt-gamma activation analysis ( PGAA) , and (3) instrumental neutron

activation analysis (INAA). The same 300 mg portion of mussel homogenate was analyzed in sequence by each instrumental technique.

Several checks were instituted during the study to evaluate the

accuracy of the concentrations obtained. These included intercanparison of

the three different techniques and the analysis of Standard Reference

Materials to evaluate the data following analysis. Using the same 300 mg

portions for the sequential analyses eliminated questions of problems in

agreement due to inhomogeneous material. Possible contamination from the

homogenization, sampling, and storage processes was investigated with an ultrapure water blank, and found to be negligible.

This combination of techniques (BFP-XRF, PGAA, and INAA), was used to

analyze mussel homogenates for a total of M3 elements. The compiled results

generally showed good agreement. However, seme slight differences between

techniques were observed for some of the elements. The causes for the

differences are currently being investigated. Additional measurements are also in progress to increase the number of elements analyzed by more than one technique. This new multi-element approach using instrumental nuclear and

atomic methods will provide the data base needed for environmental evaluation. This multi-element data will allow for the evaluation of source contributions (e.g., pollutant vs. natural environmental contributor) for a realistic assessment of the health of an aquatic community.

26
5. High Repetition Rate Tunable Laser System for Atomic Spectroscopy

( 26108 )

J. R. DeVoe, M. S. Epstein, J. C. Travis, and G. C. Turk

Tunable dye lasers have proven to be valuable excitation sources for

the sensitive detection of atomic or molecular species. The dye lasers most

widely used fcr analytical applications are optically pumped by nitrogen,

excimer, or Nd:YAG lasers, and furnish pulses a few ns long at rates of 10 to

25C Hz and energies from approximately 100 yJ to 100 mj. Cu-vapor-laserpumped dye lasers provide pulse energies near the lower end of this range

(-1 CO yj), but at a 5 - kHz repetition rate, thus providing average power

competitive with high energy pulsed lasers or with continuous wave lasers. A

1 0-W Cu-vapor laser has been acquired to explore several anticipated advantages of this energy delivery mode. Among these advantages is increased

photo-excitation efficiency, since the ratio of photons absorbed to incident

photon flux diminishes as peak powers approach and exceed optical saturation

levels for atomic systems. Because of this improved photon use efficiency,

signal averaging time to achieve a given signal-to-noise ratio is less than

for a system with higher peak power but equivalent average power. Additionally, for flame applications, every atom passing through the laser interaction volume is illuminated by one or more pulses at typical beam diameters

and gas velocities, in spite of the low (2x1 0~^) optical duty factor.

A suitably modified frequency-doubled dye laser pumped by the Cu-vapor

laser was used for preliminary laser-enhanced ionization (LEI) and laserinduced fluorescence (LIF) studies in flames. For the present configuration

of the laser, LIF is the more sensitive method, and studies are continuing to

compare limits-of-detection and precisions to conventional methods and to LIF

with high-powered pulsed lasers. Detection limits for LEI are inflated by

electrical interference (RFI) emitted by the Cu-vapor laser and by the

inability of a single excitation step to provide a suitably high ionization

efficiency

Future plans for the laser system include completion of the fluorescence study and investigation of the application of the Cu-vapor laser

(alone) to the opto-acoustic detection of NO2 , with staff in the Gas and

Particulate Research Division. The intended application of the laser to LEI

could be further pursued by acquisition of a recently-announced dye laser

optimized for Cu-vapor laser pumping, to be used in conjunction with the

presently-used dye laser for stepwise LEI. The resulting two-color laser

system would then be suitable for future application to high-repetition rate

resonance ionization mass spectrometry (RIMS), with inherently less RFI t nan

the LEI application due to the shielded detector.

6. Development of a High Accuracy Spectrometer for Laser-Enhanced

Ionization (26108)

F. C. Ruegg, J. C. Travis, and G. C. Turk

As the utilization of Laser-Enhanced Ionization spectrometry (LEI' f : trace metal analysis has increased, the need has arisen to develop ar. LEI

spectrometer for routine use rather than for research. Toward that «r. goal is to use a mi cr o-computer to control and/or monitor critical • ~

mental variables, and to collect, store, display, and process data.

27
Basic instrumentation for LEI includes a pulsed dual wavelength tunable

dye laser, an analytical flame such as used in atomic absorption spectrometry, electrodes that pass current through the flame, and appropriate

electronics required to detect the changes in flame current caused by LEI.

During the past year we have designed and built a 3 channel "sample-andhold"/analog-to-digital converter interfaced to a 16 bit microcomputer

purchased from the NBS storeroom. This device allows us to store the

amplitude of each LEI signal pulse in computer memory, along with the outputs

of laser power meters which monitor the pulse-to-pulse fluctuations in laser

power of the two laser beams used for LEI. With this information in computer

memory, we can test for correlations between LEI signal fluctuations, and

fluctuations in power of either, or both, laser beams. When such a correlation is found, the functional dependence of LEI signal on laser power can be

determined, and the LEI signal can then be corrected for changes in laser

power. We have demonstrated a greater than 3-fold improvement in signal-tcnoise ratio utilizing this procedure.

A Fizeau laser wavemeter has also been added to the LEI spectrometer

which allows accurate determination of the laser wavelengths. When software

development is complete, the fluctuations in laser wavelength will also be

monitored and corrected under computer control.

Plans for the near future include further software development for

routine analysis, together with improved computer control of laser wavelengths. One goal is the measurement of LEI spectra and display of data in 3 dimensions — 1st excitation wavelength vs. 2nd excitation wavelength vs. LEI

signal. Such spectra will reveal subtle as well as gross interf erences , and

thus be an aid in assuring accurate analysis.

7. The Determination of Nickel in Petroleum Products Using Laser-Enhanced

Ionization Spectrometry (26108)

G. C. Turk

The sensitivity of Laser-Enhanced Ionization spectrometry (LEI) for

trace metal analysis has been exploited in helping to solve a difficult

chemical analysis problem in the oil industry. The determination of Ni in

petroleum process streams is important since Ni can act as a poison when

deposited upon the surface of catalysts. The heavy oil flash distillate

sample used in this study is typical of petroleum process streams that might

be used in hydrotreating reactors. The determination of Ni before and after

hydrotreating is a useful monitor of catalytic activity. Conventional

methods of analysis have had only marginal success in achieving the precision

and accuracy required for this purpose. This work was done in cooperation

with Drs. J. D. Webb and A. R. Forster of the Shell Development Company, and

Dr. G. J. Havrilla, a former NBS postdoctoral fellow now employed by the

Standard Oil Company of Ohio.

The concentration of nickel present in the samples was on the order of

10 ppm, orders of magnitude greater than the LEI detection limit for Ni of

0.08 ppb. This excess sensitivity allows the samples to be highly diluted

before aspiration into the flame for LEI analysis. A high dilution factor

minimizes the possibility of interf erences caused by differences in viscosity

between samples and standards. In this case we used a 1 to 100 dilution. The

28
Ni concentration was determined with a precision of 1 . 5% (at 95? confidence)

and a ratio of 3 ignal to background noise of over 700 was obtained. Accuracy

of the analysis was verified via an accompanying determination of Ni in SRM

1 63 i»b Fuel Oil. The success of this work has led to the construction of LEI

spectrometers ac both the Shell Development and Standard Oil companies.

8. An Evaluation of the Long-Term Stability of N3S Glass and Thin Metal

Film Transmittance SRM's (15310)

R. W. Burxe, R. Mavrodineanu , and M. V. Smith

The first glass filter optical transmittance standards, SRM 930, were

issued by NES-CAC in March 1971; the metal-on-quartz filters, SRM 2031, were

issued in 197 7 . To date, more than 1000 sets of SRM 930 and approximately

90 sets of SRM 2031 have been purchased from NBS by various scientific and

industrial organizations throughout the world.

At the time of issue, data on the transmittance stability of each set

is limited typically to a period of 5 to 9 months. However, through requests

from users for NBS to verify or recalibrate these SRM’s on an intermittent

basis, appreciable data have been acquired on the long-term stability of many

sets of SRM 930 that have been in service for mere than 10 years and also for some 20 sets of SRM 2031 that have been in use for 3 to 5 years. The maximum

change in the transmittance of these SRM’s over these time periods has net

exceeded 0.5? relative and has averaged 0.3?* For both types of SRM’s the

transmittance has increased with time.

At the time of certification, the uncertainties in the transmittance

values of SRM 930 are 0.5? relative and of SRM 2031, 1?. Long-term stabilities are not specified because they have not yet been rigorously established.

Precautionary statements are made, however, that aging and use of these SRM's

under adverse conditions could cause the transmittance to change as much as

1? relative in a year. It is therefore reassuring to find that, after

multiple years of use, the transmi ttances of those SRM’s that have been

remeasured periodically are still within the uncertainti es specified on the

original certificates.

Studies of the long-term stability of the NBS glass and thin metal film

transmittance SRM’s in the ultraviolet and visible regions of the spectrum

will be continued. Additionally, work is in progress to extend the measurement capability of the high-accuracy spectrophotometer into the near infrared. This extension will provide the instrumentation necessary for

establishing the transmittance stability of these SRM's from the current

upper wavelength limit of 0.8 pm to 2.5 urn.

9. The Use of the 3ox Plot to Describe Heterogeneity of Iron Samoies

(15310)

J. Norris

Current practice in the study of compositional heterogeneity using

emission spectroscopy involves the acquisition of large amounts cf d . representing many selected portions of the intermediate and final form:

29
the SRM’s. These data include replications of the individual portions that are necessary to provide measures of method precision from which heterogeneity can be estimated. Statistical programs have been used to provide the

averages and standard deviations for all sets.

The materials studied may vary frccn 10 cm square sections of a steel

production ingot to the final 3*5 cm diameter rod. Other material types may

vary from tapered cones on cast SRM's to 6.4 cm diameter bars for aluminum.

Each material has a specific surfacing method; sanding for steels and nickel

base, and lathe turning for aluminum, copper and lead. The excitation used

samples in an area approximately 6 mm in diameter. Depending on the material,

the sample mass is about 2 mg.

Tests as carried out at present may involve between 40 to 80 positions

and 1 60 to 320 individual determinations. It is easier to distinguish

between significant variations due to heterogeneity and those due to the

inherent variability of the measurement if a box plot is used to present the

concentration pattern as a series of x's which represent positions on the

metal specimens. This picture dramatically shows measurement precision as a series of closely spaced x’s. Material variability is indicated when

measurements taken at an adjacent position result in closely spaced x’s whose

concentrations do not overlap the other measurements . Studies carried out

thus far have identified within specimen variabilities that are outside

method precision and between specimen variabilities that involved smooth

concentration gradients from end to end or discrete steps in concentration

resulting from material fabrication.

These plots provide a quick, visual comparison of the patterns

developed by different elements in the material. This can be useful in

determining which elemental combinations produce heterogeneous concentration

distributions and which are to be avoided. Patterns can be frequently

observed as combinations of elements such as Mn/S, Nb/C, Ca/Mg, Si/Ti.

Material specifications are continually changing. Current SRM's must

represent the best homogeneity available with modern production methods if

the SRM is to be useful over its 10 year (plus) intended lifetime.

10. Redetermination of the Atomic Weight of Gallium (15310)

J. W. Gramlich, L. A. Machlan, and L. J. Powell,

The two most recently reported literature values for the atomic weight

of gallium, one by mass spectrometry and the other by precise coulometric

assay of gallium and arsenic, have significantly different values. To

resolve this discrepancy, the atomic weight of a reference sample of gallium

(SRM 994) has been determined by combining high precision mass spectrcmetri

methodology with high accuracy chemical assay to provide synthetic calibration mixes of known isotopic composition. The gallium separated isotopes were assayed gravimetri cally as (C 5 H

5 ) ^AsGaCln with the small soluble portion

being determined by isotope dilution mass spectrometry

Seven calibration mixes and samples of the SRM were intercompared

independently by two analysts using different mass spectr ometers . A comparison of the relative isotopic abundance ratios obtained for the calibration

mixes with the gra vi met ri call y calculated values produced a correction factor

30
for sources of systematic error. By applying this correction factor to the

relative isotopic ratio obtained for the SRM, a bias free or absolute

isotopic abundance ratio was calculated.

The atomic weight calculated from this work is 69.72307 ± 0.00007. This

value is in agreement with the most recently published mass s pectr ometri

value of 69.723 ± 0.003. Although this work will not change the IUPAC

recommended value for the atomic weight of gallium due to reported isotopic

variations in commercially available sources, it will provide a highly

accurate reference material for this element.

Future plans include determining the atomic weights of: lithium, which

is of interest to the nuclear industry, and, via the stiochiometry of LiNbO-,

to the solid state industry; nickel, titanium, zinc and germanium, whose

atomic weights are the least accurately known, with uncertainties ranging

from 1 :1 500 to 1 :6000.

1 1 . Flow-Injection for On-Line Standard Addition Calibration Using a Wavelength-Modulated DCP Spectrometer (15310)

'

M. S. Epstein

Chemical interferences induced by sample matrix constituents are the

primary cause of inaccurate measurements when a direct-curr ent plasma is used

as a source for emission spectroscopy. While chemical buffers (i.e.,

2 mg/mL Li) can somewhat reduce the magnitude of the interf erences , signal

enhancement or suppression of up to 30 percent is often observed in buffered

samples with complex matrices. Furthermore, the addition of high concentrations of buffer often results in high analyte blanks. The only other

alternative is the standard addition procedure, which can be extremely time

consuming when a large number of samples must be analyzed. Therefore, we have investigated a flow-injection analysis (FIA) procedure for ’’on-line"

standard addition.

The flow-injection system is peristaltic pump based with 9 channels and

the capability to select one of four standard solutions for automatic

injection and mixing with the sample stream. While the present system is

manually programmed via a terminal, a dedicated microcomputer could easily be

used to implement an automatically controlled system. The detection system is an echelle spectrometer equipped with a rapid-scanning refractor plate for

background correction. This rapid wavelength modulation system is required

when small sample volumes are employed with the flow injection system, since

it provides an essentially ” simultaneous" background correction.

This system has been employed for standard addition calibration in the

determination of Cu in SRM 2673 (Urine) diluted 1:1, Co in SRM 1695 (River

Sediment), and Na and Ni in Fuel Oil (I 639a,b). Accurate results consistent

with results from other analytical techniques were obtained for all analyses

with a 50 percent savings in sample/standard preparation and analysis tin-;.

Furthermore, sample handling blanks, significant in the determination of N :

,

were minimized.

Ultimately, the FIA system will be put under complete computer c r‘ and interfaced with an autosampling device. This will be necessary f

- *

31
involving small samples (<1 mL) where the flow timing parameters are critical. The FIA system will then be used as a transportable sample introduction

device for use with ICP, flame emission and flame atomic absorption

atomizers, as well as the DCP.

12. Speciation of Tributyltln in Seawater (15310)

T. C. Rains

Organotin compounds are frequently used in the production of plastics

and in antifouling 'paint* coatings for ship hulls to minimize the accumulation of species such as algae, fungi, bacteria, and mollusks. The toxicity

of these chemicals is related to the chemical form of the organotin and some

of these compounds may be toxic to humans as well as marine organisms. The

goal of - this work is to develop a method for analyzing for the various

chemical forms of tin including mono, di, and tributyltin species.

The leach rate of these toxic compounds has a significant effect on the

service life of the coatings, the antifouling efficiency, and the environmental availability of potentially toxic materials. At the present time the

Navy is anticipating a change from copper based antifouling coatings to

organotin based coatings which can be formulated to leach at a lower rate

with the same degree of antifouling effectiveness. Although this move is

expected to result in an extension of the present service life from 24 months

to five years or more, little is known about the behavior of these organotin

compounds in the marine environment.

Several analytical approaches are currently in use for the determination of Sn(IV), mono-, di-, and tributyltin species in seawater. The basic

steps of the generic analytical methodology are the separation of the

organotin species, the preconcentration step, and the analytical measurement.

Major analytical problems are associated with each of these step which must

be resolved to make an accurate determination of total tin and tributyltin.

Three of the current analytical approaches are hydride generation, chelationsolvent extration, and ion-pair liquid-liquid extraction.

The Naval Ocean Systems Center (NOSC) in San Diego has developed a hydride generation technique for the preconcentration and separation of the

tin species. The method requires an adjustment of pH of the seawater sample

followed by production of the organotin hydrides using NaBH^. The hydrides

are collected in a liquid nitrogen trap and then separated on the basis of

their relative volatility. The method is slow in that only 8 to 10 samples

can be analyzed per day. Also, the accuracy of the method has not been

verified by any other analytical technique.

Our task is to evaluate the precision and accuracy of the method used

by NOSC for the determination of organotin species in seawater. While the

species have been found to be separated by the hydride technique, the

recovery was found to be incomplete and variable. Future plans include an investigation of liquid-liquid extraction as a means of separation and

preconcentration and modification of the hydride generation method presently

being used. Another approach would be to take advantage of the organophilic

properties of these organotin species and preconcentrate them on a nonpolar

32
stationary phase directly or by headspace analysis from seawater. The

separation of the species is performed by liquid-phase technique with

laser- enhanced ionization spectrometry or electrochemical detection.

1 3 . Physical and Chemical Properties of Aerosols Produced by the Spark

Discharge C’53'0)

R. L. Watters, Jr, R. A. Fletcher, R. L. McKenzie, and J. A. Small

Some of the most advantageous analytical spectr ometric techniques

involve the direct sampling of solid material. Such an approach eliminates

time consuming dissolution procedures and the errors associated with analyte

less and contamination. However, techniques such as optical emission

s pectrometry , spark source mass spectometry, and microprobe mass spectrometry, which use direct solid sampling, can exhibit systematic errors due to

the combined effects of bias in the sample transport and excitation pro- cesses. As a result, each instrumental technique requires calibration

standards for each type of sample matrix that is to be analyzed. The key to

alleviating this need for standards in every possible matrix is to develop

analytical techniques that do not exhibit bias from one matrix to another.

When such instrumental techniques consist of a sampling step followed by an excitation step, it is essential that bias in each of these steps be examined

separately. To focus on the transformation of sample material from the bulk,

we have been examining the physical and chemical properties of aerosols

generated by condensation of vapor produced by the spark discharge.

The spark is a useful means of converting solid conducting samples into

an aerosol for introduction into an inductively coupled plasma (ICP).

Particle size distributions have been measured for pure materials (Fe, Cu

,

Pb , Al, W, Mo) and the effects of spark repetition rate and peak current have

been recorded. The aerosol produced is nearly monodisperse with a mean

diameter of about Q.1 urn. A few larger particles ( —5 — 10 pm), which a~e

nearly spherical, have also been detected using scanning electron microscopy

(SEM). The smaller particles form loosely bound chains and clusters when

collected on screens for SEM analysis. These chains and clusters apparently

break apart in the mobility analyzer, which registers the 0.1-yra fundamental

aerosol units. Further experimentation is needed to determine whether the

clusters are formed in the aerosol stream or are caused by the electrostatic

collector. •

Preliminary x-ray analysis of the chains and spheres using the

analytical electron microscopy (AEM) , has indicated a compositional difference between the chains and the spheres. To quantify the chemical composition of the collected aerosol, a series of brass SRM’s has been examined t; determine Zn/Cu ratios for the particle size groups separated by a two-stag

filter collector. These stages separate the submicrometer from the 8-'?

group. Particles on each filter were dissolved and analyzed by ICP. Initial

results indicate a bias in the Zn/Cu ratio for particles collected by b:t\

filter stages. These data also indicate that the mobility analyze^ ccur.t :f a small fraction of the aerosol stream can be used to provide a ratio fer t - mass balance of total material sampled. At present, no mass flew r used and the spark-ICP analytical instrument must analyze for every

in the sample and normalize the data to 1001, thereby substantially - ing the error. Additional measurements of this type are in progress .

33
The continuation of this work will include using SEM to examine the

filters to ascertain the degree of cluster formation. This will provide a comparison between the previously measured characteri sties of the aerosol

sampler and the actual size ranges collected in these experiments. The

studies will include other alloys to examine the effects of alloy physical

properties and chemical composition on sampling.

The sampling and collection schemes in the present experiments will be

used to assess the feasibility of real-time analysis of ambient aerosols.

Where results indicate analytical promise, sampling devices such as the spark

will be coupled to the ICP, DCP, or chemical flame as excitation sources for

optical emission analytical spectrometry with the ultimate objective of

providing an analysis technique free from matrix effects.

1 *4. Characterization of Autoionizing Levels in Beryllium with Resonance

Ionization Mass Spectrometry (15310)

~

J. D. Fassett, L. J. Moore, C. W. Clark, W. W. Smith, and

T. B. Lucatorto

Autoionizing levels are discrete electronic levels of an element that

are at energies greater than the ionization potential. In general, autoionizing levels of most elements are not well characteri zed or understood.

Resonance ionization mass spectrometry (RIMS) has the promise of sensitivelydetecting these levels. The single or multiple absorption of photon(s) from

a discrete electronic level below the ionization continuum results in an enhancement in the ionization probability of the element, since the cross- section for absorption is greater to this autoionizing level than into the

surrounding continuum. The excited atom spontaneously loses an electron to

become an ion. We have investigated Be because of the extensive theoretical

attention that has been given to the treatment of its autoionizing states.

Since Be is the simplest atom that has two electrons outside a closed shell,

it is the prototype for the study of electron correlation. There have been

at least 8 theoretical estimates of the position of the 1s 2 2p 2 1s0 autoionizing level of Be which range from 1800-71 00 cm"*1 above the ionization potential. We initiated experiments to establish the position of this

autoionizing level.

A resonance line has been observed at 262.5 nm that we ascribe to the

1s 2 2p 2 autoionizing level of Be for the following reasons: (1) the power

dependence of the ionization is squared, indicating a 2-photon process; (2)

the polarization dependence of the transition, delta J=0, is correct; and,

(3) the line width and position are theoretically tenable. The experimental

position, 100*1 cm" 1 above the ionization potential, is 800 cm" 1 lower than

the closest theoretical calculation. If the intershell correlations of the K and L shells are included in this theoretical calculation, the experimental

and theoretical energies differ by only 100 cm" 1 .

In the preliminary experiments in which RIMS of Be was demonstrated, a series of low intensity lines was observed in the spectra. These lines have

been identified also as autoionizing transitions, in this case representing

3-photon transitions resonantly enhanced by a near-lying 2-photon transition.

These lines are transitions from the 1s 2 2s 2 ground state to the 1s 2 2snd

3*4
Rydberg series where we observe n=5”15 of this Rydberg series. These

high-lying members of this Rydberg series similarly have never been experimentally observed.

Although this 3tudy of 3e is experimentally complete, the observation

of 2- and 3-photon transitions to autoionizing levels promises to explain

many of the previously unassignable spectroscopic features observed in RIMS

spectra. Furthermore, autoionizing levels could be used in schemes to

increase the sensitivity of the ionization process by making one of the

photons in a multiphoton absorption process resonant between an autoionizing

level and a discrete level below the ionization continuum. This work has

broadened our basic understanding of both the resonance ionization mass spectrometry technique and atomic physics.

15. The Determination of Iron in Serum and Water by Resonance Ionization

Isotope Dilution Mass Spectrometry (15310)

J. D. Fassett, L. J. Powell, and L. J. Moore

Resonance ionization mass spectrometry (RIMS) is a relatively new technique that combines optical spectroscopy with mass s pectr ornetry . The

technique exploits lasers to selectively and efficiently ionize gas phase

atomic species. When the laser is tuned to a discrete resonant electronic

transition of an element, the ionization probability increases many-fold due

to the stepwise absorption of photons. Most of the initial applications of

RIMS have been made with modified thermal ionization mass spectrometers

(TIMS). RIMS can be applied to TIMS measurement problems where lack of

sensitivity (failure to produce ions) and/or non-selectivity (isobaric

interferences) result in fundamental limitations. The RIMS potential is

demonstrated by its application to the accurate analytical determination of

iron, an element for which thermal ionization is particularly insensitive.

Resonance ionization mass spectrometry has been used in conjunction

with isotope dilution to determine the iron content of SRM 909 (Human Serum'

and SRM 1643b (Trace Elements in Water). Iron was thermally vaporized from a filament at 1250 K. We have computed from the Saha-Langmuir expression that

the Fe°/Fe+ ratio is -1 0

1 2 at 1250 K, and from this we estimate that the RIMS

system is 10? mere sensitive than TIMS. This estimate includes losses from

the duty cycle of RIMS at -10“5. A one-wavelength, two-photon ionization

scheme was employed utilizing UV radiation at 283.6 nm provided by a Nd: YAG

pumped dye laser with frequency doubling. The mass spectrometer used was a 15 cm radius magnetic sector instrument of NBS design. The linearity of the

detection system was verified by the determination of the 57p e/5op e patios in

a set of gravimetrically prepared isotopic calibration mixes, over a 57pe/56pe ratio range of -750. The precision and accuracy of the measurements were typically 2-3 percent. The mass spectr ometri c loading blank is

presently the limiting source of error. The concentration and uncertainty

( 95 % confidence limits) of the certified values of Fe in SRM 909 are 1.9 U t 0.29 yg/g and in SRM l6^3b are 99.2 ± 8.3 ng/g.

This work represents the first isotope dilution application using RIMI.

Plans for extending this research include an evaluation of systematic b i an r; involved in the ionization and measurement processes, with the i nt <=>:.* . ' developing highly sensitive and selective multielement isotope dilutin'

capabilities at precisions, and accuracies well within one percent. 7 ..

35
evaluation will require a better understanding of the resonance ionization

process itself, particularly with respect to the possible effects of isotopic

discrimination. The accurate measurement of pulsed ion currents using a time-gated detection system will be investigated. One effective application

of this research could be the determination of chromium-vanadium-titanium

trace element mixtures for which chemical separation of isobaric interferences is difficult and for which the sensitivity and elemental selectivity of

RIMS would be ideally suited.

16. High Precision Isotope Ratio Measurements of CO? (15310)

I. L. Barnes, P. Morales, J. Gramlich, and W. A. Bowman, III

The technique of isotope dilution mass spectrometry (ID/MS) has

developed during the past fifteen years into the definitive method for the

analysis of trace elements in solid samples. As a logical extension of this

technique, this project was intended to develop the instrumentation and

methodology for the determination of traces of compounds of carbon, oxygen,

nitrogen, and sulfur in various gas mixtures by ID/MS. The determination of

the concentration of carbon dioxide in nitrogen and air was selected as the

first analytical problem with application to the certification of a series of

gas Standard Reference Materials.

A new and unique 30 cm radius, 90° deflection mass spectrometer

designed for high precision gas analysis was constructed. Salient features

include an electron impact ionization source, a new ultrastable emission

regulator, a triple, deep-Faraaay-cup collector, and a direct ratio reading

measurement system. The instrument is automated and controlled by a small

computer. A dual gas sample storage and introduction system and an isotope

dilution mixing line were also constructed.

Initial measurement precision has been quite satisfactory. As an example, we obtain delta (parts per 1000) 1 values of +0.3892 ± 0.0006 and

+2.1993 ± 0.0005 for two CO 2 standards which may be favorably compared with

the best recently published values of +0.389 ± 0.001 and +2.199 ± 0.004.

Similar precision has been obtained in the measurement of the isotopic ratios

of 7 other standard materials commonly used in the light stable isotope

community. Isotope dilution measurements are currently being made on samples

of a research cylinder of CO 2 in air. When complete, a series of measurements

will be made on a series of SRM samples of CO 2 in nitrogen.

It is planned, in future work, to measure a series of samples at very

different concentrations, to start a redetermination of the atomic weight of

oxygen, and to explore the possibility of extending the system to compounds

of nitrogen and sulfur.

17. Certification of Nuclear Isotopic Standard Reference Materials (15310)

J. W. Gramlich, L. A. Machlan, B. S. Carpenter, R. R. Greenberg, and

J. R. Moody

Reference materials with accurately known isotopic compositions are essential for instrument calibration in the nuclear industry to assure the

safeguarding and accountability of nuclear materials. Two sets of uranium

isotopic Standard Reference Materials have been certified for isotopic

36
composition; one set for use in destructive assay (DA) by mass spectrometry,

and the other set for non-destructive assay (NDA) intended for gamma spectrometry calibration.

The destructive assay material consists of a renewal of three of a series of 17 uranium isotopic standards, ranging from depleted to highly

enriched 235u abundance. The renewal SRM’s U-030a, U-020a and U-005a have

been certified with an accuracy a factor of two better than previously

certified uranium isotopic standards. The decreased uncertainty in these

measurements is the result of improved analytical methodology, both in the

chemical assay and the mass spectrometry

The development of a Standard Reference Material for non-destructive

assay represents a cooperative effort between NBS, The Commission of the

European Communities, Central Bureau for Nuclear Measurements, Geei, Belgium,

and the U.S. Department of Energy, New Brunswick Laboratory, Argonne,

Illinois. This Standard Reference Material (SRM 969) "Uranium Isotopic

Standard Reference Material for Gamma-Ray Spectrometry Measurements" is

intended for use in the calibration and evaluation of counting procedures for

the non-destructive determination of the 235u isotope abundance in uranium

bulk materials. SRM 969 consists of a set of five different U^Qg powders

with 235 u abundances of 0.31 » 0.71, 1.94, 2.94 and 4.46 weight percent,

together with an empty container. The empty container is provided for

measuring uranium bulk material of unknown 235y abundance. SRM 969 was prepared as a set to permio accurate enrichment measurements on low enriched

uranium materials by testing the theoretically expected linear relationship

between 235y abundance and the counting rate of the 185.7 KeV gamma-ray of

. Each SRM sub-unit is made up of 200g of UgOg powder sealed in a tamper

proof aluminum can. Each container was manufactured to rigid specifications

and thoroughly tested. SRM 969 will be issued in Europe by the Central

Bureau of Nuclear Measur eme.nts as Reference Material EC 171.

The issuance of these two sets of uranium isotopic SRM’s is expectec to

substantially improve, on an international scale, accountability measurements

in the nuclear industry.

18. Determination of Trace-Level Cr(VI) in the Presence of Cr(III) and

Fe(III) by Voltammetric Flow-Injection Analysis (15310)

K. W. Pratt and W. F. Koch

The toxicity of Cr(VI) in natural waters is much greater than that cf

Cr(III). Hence, the oxidation state specific determination of Cr(VI) at

trace levels is of significant interest in environmental analyses. v ost

trace-level techniques are element-specific but do not differentiate among

different oxidation states of a given element. A preliminary separation of

Cr(VI) from Cr(III) is thus required for determinations based on these

element-specific methodologies.

Flow- inject ion analysis with amperometric detection provides a simp'.- , inexpensive method for the determination of Cr(VI) at trace levels in t.n presence of Cr(III). Two significant improvements in this technology

been accomplished. First, the vibrating wire electrode (VWE) has

applied as an amperometric detector for the determination of Zr VI : . flow-injection analysis. Use of the VWE has effected a IC-tc Z

37
increase in the sensitivity of the determination. This improvement is a direct consequence of the increased rate of mass transport resulting from the

vibration of the electrode. Detection limits for Cr(VI) at the VWE are at

the ppb level. The second improvement is the elimination of the interference

of Fe(III) in the voltammetric determination of Cr(VI) by using H^POii instead

of HC1 or H 2 S04 as the supporting electrolyte. The Fe(III) in the sample is

complexed by the (HP0ij)2-, and the Fe(III)- (HPO4 ) 2- complex is not reduced at

the electrode at the potential used for the detection of Cr(VI). Substitution of H 24 P2 O7 for H 3 PO14 has permitted a still broader range of potentials to

be used for the amperometric detection of Cr(VI) without interference from

Fe(III). Direct determinations of Cr(VI) without prior separation of Fe(III)

and Cr(VI) are thus possible for the first time in matrices typically

encountered in natural waters.

Future directions for this project include application of this methodology to the determination of Cr(VI) in marine and environmental samples. In

addition, the electrocatalysis of the reduction of Cr(VI) at Pt and Pd

electrodes by adsorbed iodine will be studied, with a view toward optimizing

the reproducibility of response of the electrodes. Application of the VWE to

determinations of other electroactive species by flow-injection analysis are also anticipated. It is expected that this procedure will permit the

determination of the various chemical forms of elements in solution.

1 9. The Measurement of pH and Acidity in Rainwater: Development of a Research Material/Simulated Rainwater (l5310l

W. F. Koch, G. Marinenko, and Y. C. Wu

The research effort to provide a meaningful basis and quality assurance

for analytical measurements in acid rain studies has continued this year with

noteworthy advances. This long-term project has been in support of the

National Acid Precipitation Assessment Program (NAPAP) at the request of the

Environmental Protection Agency (EPA) . It encompasses the evaluation of

existing methodologies for analytical measurements, the development of

improved measurement procedures which address the unique characteristics of

acid rain, and the development and characterization of stable, homogeneous

research materials in solution form to aid in the analysis of rainwater. The

primary focus of this year’s activities has been in the measurements of pH

and acidity.

A round-robin exercise was conducted early in the year to test the

efficacy of using dilute solutions of a strong acid as working standards for

pH measurements in acid rain. Twelve laboratori es , distributed among

government, industry and academia, voluntarily participated in this test. The

results prove conclusively that the residual liquid junction potential can seriously bias pH measurements and that the use of matrix-matched pH

standards will significantly reduce this bias. These matrix-matched pH standards should be consistent with the National pH scale as maintained through

the NBS Standard Reference Materials (SRM's) pH buffers so that measurements

of pH be as thermodynamically meaningful as possible and to avoid confusion

caused by multiple pH scales. To this end, a Research Material, RM 8409,

Simulated Rainwater, has been developed and is now available. RM 8409 is a set consisting of two 50-mL solutions in polyethylene bottles. The pH values

of the solutions have been established through the use of potentiometri

hydrogen cells without liquid junction and confirmed by coulometric titration

38
and ion balance calculations. Guidelines for the measurement of pH in

rainwater have been developed which incorporate RM 8409. This recommended

procedure has undergone statistical ruggedness testing to evaluate the

effects of various parameters on the measurement. The parameters tested

include temperature, stirring, equilibration time, dilution, immersion depth

of electrodes, and the addition of neutral salts. The effect of carbon

dioxide on the pH value of rainwater will be evaluated in the future. The

effect of carbon dioxide on the value of the acidity of rainwater has been

investigated and found to be significant, particularly in rainwater of low

acidity. It has been recommended that rainwater be deaerated by purging with

nitrogen or argon prior to titration and that the titration be carried out

either by the method of Gran or by potentiometric titration to the inflection

point. A great deal of research remains to be done on quantifying the

effects of carbon dioxide due to its complex equilibria in solution, its slew

reaction kinetics, and its easily perturbed partial pressure.

Work leading to an SRM for rainwater will be initiated this year.

Recommended procedures for the measurements of pH and acidity will be issued

as an integral part of the certificate. This will represent the first of a series of matrix- specific pH standards. (Future standards will include

seawater and biological fluids.) Also, it will be the first aqueous SRM for

anions and for specific conductance. The acid rain project will expand this

year to begin investigating the needs for standards and analytical procedures

in dry deposition, focusing on the assessment of analytical errors and on the

stability of solutions containing inorganic species at the 1 0”7 g/g and below

levels

20. Uranium and Sulfur Isotopic Tracers in the Environment (15310)

J. D. Fassett, W. R. Kelly, and P. J. Paulsen

Contamination of the atmosphere can occur as the result of nuclear

accidents and can be sensitively monitored by using high precision mass spectrometry. In collaboration with the DOE-Environmental Measurements

Laboratory, we have determined the 235y/238u ratios in several air filters

that were flown at high altitudes and that were intended to intercept debris

from the Soviet reconnaissance satellite, Cosmos 1402, which reentered the

atmosphere over the Indian Ocean on January 24, 1983. Cosmos 1402 was a four-ton space craft powered by 55 kg of enriched 2 35y and was launched on August 30, 1 983. This type of satellite normally operates for 6-7 months

before being boosted to a stable orbit expected to last 1000 years. Cosmos

1 402 had been turned off December 28, 1 983, and the orbital boost apparently

failed in this case.

The analytical procedure used was as follows: approximately 5 g of

filter is spiked with a small quantity (10-20 pg) of 2 33u spike and wet ashed

using a mixture of HClOij/HNO^. The U is separated using anion exchange

chr omatography [1]. This procedure separates U in pure form and with a r.;gn

yield for mass spectrometri c determination.

The three filters that have been analyzed thus far contained at: u pg/g of 2 38(j and showed enrichments of 2 35u of 25? above blank f ; ;

*

. •

material. The data indicate that Cosmos 1402 debris was intercepted,

information will be used by EML to plan future flights.

39
An investigation has been initiated on the use of sulfur isotopes to

trace SO2 emissions from coal-fired power plants. There are two possible

approaches in the use of sulfur isotopes for this purpose. One is to use the

natural variability in the isotopic composition to identify the source of

emissions and the other is the intentional release of an artificially

enriched isotope of sulfur from a particular power plant. The former

approach is being tried using size fractionated aerosol samples obtained from

the Deep Creek Lake Experiment carried out in the summer of 1 983. The

enriched isotope approach may be attempted in the near future using centrifuge-enriched 34$. For this approach to succeed, the natural fractionation

effects will need to be differentiated from the intentional 34g enrichment.

One way to do this is to use the 32s/33s ratio as an internal standard to

remove natural and instrumental fractionation effects frcm the measured

3^s/32s ratio. This approach has yet to be demonstrated for S, but it is

planned for the near future.

[1] W. R. Kelly and J. D. Fassett, Anal. Chem. 55, 1040 (1983).

21 . Standard Reference Materials

B. I. Diamondstone

As in past years, the Division has put considerable effort into the

process of certifying Standard Reference Materials (SRM’s). The combination

of research and certification analyses account for approximately thirty

percent of the total staff effort. The expertise required to successfully

implement this program comes from all of the groups in the Division. Nearly

all members of the Division participate in one or more aspects of acceptance

testing, homogeneity evaluation, or accurate analysis, leading to the

certification of inorganic constituents in potential SRM materials.

Listed below are seven different areas of research that were funded by

the Office of Standard Reference Materials during the past year. This

portion of the STRS OSRM funding is intended for the preliminary research

necessary to develop the methodologies required for the actual production of

SRM’s. The actual certification for chemical composition on a marketable

standard is carried out as a WCF project.

40
SIRS Projects Supported by OSRM During FY 84

Task Description Effort, SY

Gases in Metals Research leading to the developmnent of 0.5

methods and procedures for certifying oxygen,

hydrogen, nitrogen, and carbon in a variety

of metal matrices.

Particle Size

Fraction

Research leading to the following: 0.35

1) evaluation of candidate materials and

loading procedures for the production of

a natural matrix material on filter media;

2) evaluation of the relationship of the

chemical composition of SRM 1648 to its

particle size distributions.

Cast/Wrought

Effects

Research leading to the evaluation of dif- 0.20

Terences in optical emission behavior of

cast and wrought SRM’s.

Aqueous

Electrolytic

Conductance Stds

Research leading to an understanding of the 0.25

fundamentals of conductivity measurements.

Investigate feasibility of producing

aqueous conductivity SRM’s.

pH Measurements Research leading to the development of improved 0.20

methods for making accurate pH measurements

Noble Metals Research leading to the development of proto- 0.20

type SRM’s for the certification of noble

metals on silica.

Complex Matrices Research leading to the development of 0.70

methods for the measurement of trace

elements in biological materials and

the preparation and evaluation of a Rainwater Research Material.

2.4

Listed below are approximately 75 different SRM's that were analyze

for as many as 30 different elements. These materials included metals, foss:

fuels, body fluids, foods, nuclear materials, biologicals, and glasses.

41
Standard Reference Materials Analyzed During FY 84

and Divison Effort in Staff Years

SRM Number Title Effort, SY

21 22,2123,2124

161 8

2679a

679

1 634b

650, 651 ,652

1632b

I85f

2185

44f

1818

1 5h

2033

2135

930d

2031

2400, 2400a, 2401 ,2401 a, 2402

1 290, 1290a, 1291 , 1291a, 1292

1 218

1003a

1 761-1 767

394,396,398,400

955

2670

173c

1 832

359

33e

1255a, 1256a, 1240, 1241

241 5

1 761-1 767

c 1 253

1572

976, 978a, 987.

1577

Spectr omet ric Solution Stds

V-Ni-S in Residual Fuel Oil

Quartz on Filter Media

Trace Elements in Brick Clay

Trace Elements in Fuel Oil

Unalloyed Titanium

Trace Elements in Coal

KHP (pH)

KHP (pD)

Hi-Purity Aluminum

Cl in Rerefined Oils

Plain Carbon Steel

Potassium Iodide Stray Light Std

Silicon Wafers

Glass Filters for Spectrometry

Metal On Quartz Filters

White Irons

White Irons

Silicon Steel

Glass Spheres

Low Alloy Steels

Copper Benchmarks

Porcine Blood

Trace Elements in Urine

Titanium Base Alloys

XRF Thin Films

Zircaloy

Low Alloy Steel

Aluminum Alloy

Lead

Low Alloy Steel

Copper Benchmarks

Citrus Leaves

Isotopi cs Bovine Liver

0.5

0.2

0.3

0.5

0.7

0.25

0.8

0.2

0.2

0.03

0.05

0.01

0.1

0 . 01 0.3

0.3

0.01

0.01

0.01

0.02

0.2

0.2

0.1

0.2

0.03

0.03

0.1 5

0.02

0.1

0.

0.6

0.1

0 . 1 0.04

0.1

6.7

Existing and newly developed methodologies were successfully used to

issue three environmentally important SRM’s during the past year. These

materials, milk, urine, and serum, required nearly a dozen separate analytical techniques for certification. Additional elements in these materials

will be added to the certification list during the next year. In the metals

area, a number of new materials have been certified for oxygen, hydrogen, and

nitrogen. Analytical procedures for determining these gases in metals have

not been available at NBS during recent years. In addition, uncertified

elements in existing SRM’s are continually being certified as new analytical

techniques are developed and values for previously certified elements in

existing SRM’s are periodically checked and updated as new, more accurate
methods become available. Before the year is over, nine sets of aqueous

standards will be available for use with spectr cmetri c techniques such as AAS , ICP, DCP, and spectrophotometry.

It is anticipated that next year we will see the issuance of additional

metal samples certified for hydrogen, oxygen, and nitrogen content and work

will commence on lead and aluminum standards. Work will begin on a number of

other new and reissued SRM's, including limestone, flint and plastic clays,

rice and wheat f lour , and sulfur in kerosene.
C. Outputs and Interactions

(Inorganic Analytical Research Division)

1 . Publications

Beyrich, W., Golly, W., Spannagel, G. f De Bievre, P., Wolter, W., Gallet, M.,

Machlan, L. A., Gramlich, J. W., Fassett, J. D., "The IDA-80 Measurement Evaluation Programme on Mass Spectrometri c Isotope Dilution

Analysis of Uranium and Plutonium," Nuclear Safeguards Technology 1982,

Vol I, IAEA, Vienna, Austria, 261-278 (1983).

Downing, R. G., Fleming, R. F., Langland, J. K., and Vincent, D. H. , "Neutron

Depth Profiling at the National Bureau of Standards," Nuclear Instruments and Methods, 218, 47-51 (1 983).

Fassett, J. D., Moore, L. J., Travis, J. C., and Lytle, F. E. , "The Characterization of Thermally-Produced Metastable Excited-State Atomic

Species Using Resonance Ionization Mass Spectrometry ," Int. J. Mass

Spec. & Ion Processes, 54., 201-21 6 ( 1983).

Fassett, J. D., Travis, J. C., Moore, L. J. , and Lytle, F. E. , "Atomic Ion

Formation and Measurement with Resonance Ionization Mass Spectrometry,"

Anal. Chem., 55, 765*770 (1983).

Fleming, R. F. , "Neutron Activation Foils," Chapter 10, in Calibration

Handbook: Ionizing Radiation Measuring Instruments," G. Lalos, ed..

Department of Defense (1983).

Domalski, E. S. , MacCrehan, W. A., Moody, J. R., Tewari , Y. B. , and Walker,

J. A., "Characterization of Millscale Steel Wastes," NBS IR 83*2773.

October (1 983).

Gramlich, J. W., Powell, L. J., Brletic, K. A., Murphy, T. J., "The Determination of Lead, Thallium, Copper, and Nickel in Human Liver Samples by

Isotope Dilution Mass Spectrometry ," NBS Spec. Publ . 656, 47*53

(1983).

Holden, N. E. , Martin, R. L. , and Barnes, I. L. , "Isotopic Compositions of

the Elements 1981," Pure Appl . Chem., 55^, 1 1 19 ( 1983).

Kingston, H. M., Greenberg, R. R., Beary, E. S., Hardas, B. R. , Moody, J. R.,

Rains, T. C., and Liggett, W. S. , "The Characteri zation of the Chesapeake Bay: A Systematic Analysis of Toxic Trace Elements," NBSIR

83*2698, November (1983).

Moore, L. J. , Fassett, J. D., Travis, J. C., Lucatorto, T. B. , Clark, C. W.,

"Isotopic Selectivity in Ultrasensitive RIMS," Proc . of the SPIE

Symposium, Laser-Based Ultrasensitive Spectroscopy and Detection V,

Vol. 426, 18-23 (1983).

Paulsen, P. J. and Kelly, W. R., "Analysis of Sulfur in NBS Standrd Reference

Materials by Thermal Ionization Mass Spectr ometri c Isotope 'Dilution

Abstract 184th American Chemical Society National Meeting, Kansas City,

MO, 106 ( 1983) .

44

/
Schenck, P. K., Travis, J. C., and Turk, G. C., "Studies of Physical Mechanisms in Laser Enhanced Ionization in Flames," J. Phys . Colloq., 4_4

,

C7-75 (1983).

Turk, Gregory C., Travis, John C., and DeVoe, James R., "Laser-Enhanced

Ionization Spectrometry for Trace Metal Analysis," J. Phys. Colloq.,

4^, C7-301 (1983).

Burke, R. W. and Velapoldi, R. A., "Recommended Reference Materials for

Realization of Physicochemical Properties," IUPAC, Wavelength and

Transmittance Section, August (1983).

Zeisler, R., Langland, J. K., and Harrison, S. H., "Cryogenic Homogenization

of Biological Tissues," Anal. Chem., 55, 2431-2434 ( 1983).

Downing, R. G., Fleming, R. F., Maki, J. T., Simons, D. S., and Stallard, B.

R., "Near-Surface and Interfacial Profiling by Neutron Depth Profiling

and Secondary Ion Mass Spectrometry , " J. E. E. Baglin, D. R. Campbell,

and W. K. Chu, eds., Mat. Res. Soc. Proc., 25, 655-656 (1984).

Ehrstein, J. R., Downing, R. G., Stallard, B. R., Simons, D. S., and Fleming

R. F., "Comparison Depth Profiling of B-10 in Silicon by Spreading

Resistance Profiling Secondary Ion Mass Spectrometry, and Neutron Depth

Profiling," in Third Symposium on Semiconductor Processing, ASTM

proceedings, D. Gupta, ed. (1984).

Epstein, M. S. and Winefordner, J. D., "Summary of the Usefulness of

Signal-to-Noise Treatment in Analytical Spectrometry," Prog. Analyt.

Atom. Spectrosc., 67 ( 1984).

Fassett, J. D. and Kelly, W. R., "Interlaboratory Isotopic Ratio Measurement

of Nanogram Quantities of Uranium and Plutonium on Resin Beads by

Thermal Ionization

(1984).

Mass Spectrometry ,Anal. Chem. , 56, 550-556

Fassett, J. D., Moore, L. J., Shi del er, R. W., and Travis, J. C., "Pulsed

Thermal Atom Source for Resonance Ionization Mass Spectrometry," Anal.

Chem., 56, 203-206 (1984).

Fassett, J. D., Moore, L. J., and Travis, J. C., "Resonance Ionization Mass

Spectrometry of Iron—Quantitative Aspects," in Analytical Spectroscopy , W. S. Lyon, ed., Elsevier, New York, New York, 137-142 (1984).

Fassett, J. D., Travis, J. C., and Moore, L. J., "Thermal Atomization Sources

and Resonance Ionization Mass Spectrometry (RIMS)," Proc. SPIE

Technical Symposium East '84, Arlington, V A, April 29-May 4 (1984).

Kelly, W. R., "Application of Stable Isotope Tracers to Air Pollution

Problems," Abstracts of the 12th Middle Atlantic Regional Meeting,

American Chemical Society, 60 (1984).

Kingston, H. M., Cronin, D. J., and Epstein, M. S., "Investigation of a Precise Static Leach Test for the Testing of Simulated Nuclear

Materials," Nuclear & Chem. Waste Management, Vol. 5 (1984).

45
Havrilla, G. J., Schenck, P. K., Travis, J. C., and Turk, G. C., "Signal

Detection of Pulsed Laser-Enhanced Ionization," Anal. Chem., 56_, 186

( 1984 ).

Holden, N. E. , Martin, R. L. , and Barnes, I. L. , "Isotopic Compositions of

the Elements 1983," Pure Appl . Chem., 56, 663 ( 1984).

Mavrodineanu, R., "Hollow Cathode Discharges—Analytical Applications," J. of

Res. of NBS, 89, March-April (1984).

Paulsen, P. J. and Kelly, W. R., "Determination of Sulfur as Arsenic Monosulfide Ion by Isotope Dilution Thermal Ionization Mass Spectrometry ,"

Anal. Chem., 56, 708-713 (1984).

Peiser, H. S. , Barnes, I. L. , De Bievre, P. J., De Laeter, J. R. , Hagemann

,

R., Holden, N. E. , Murphy, T. J., Roth, E., Shima , M., and Thode, H.

C., "Element by Element Review of Their Atomic Weights," Pure Appl.

Chem., 56, 695-768 ( 1984)

Powell, L. J. and Paulsen, P. J., "Determination of Hafnium in Zirconium

Metal and Zircaloy 4 Metal Standard Reference Materials by Isotope

Dilution Spark Source Mass Spectrometry," Anal. Chem., 56_, 376-378

(1 984).

Travis, J. C., Fassett, J. D., and Moore, L. J., "A Survey of Elements

Detected Using Resonance Ionization Mass Spectrometry," Proc. 2nd

Internal. Symp. on Resonance Ionization Spectroscopy and Its Applications, Knoxville, TN, United Kingdom Institute of Physics Conference

Series, Adam Hilger, Ltd., Bristol, UK, 1 6-20 ( 1984).

Travis, J. C., Turk, G. C., DeVoe, J. R., and Schenck, P. K., "Principles of

Laser-Enhanced Ionization Spectrometry in Flames," Prog. Analyt. Atom.

Spectrosc., 7, 199-241 (1984).

Turk, G. C., Havrilla, G. J. , Webb, J. D., and Forster, A. R. , "Performance

Appraisal Studies of Laser-Enhanced Ionization in Flames—The Determination of Nickel in Petroleum Products," in Proc. of 26th 0RNL-D0E

Conference on Analytical Chemistry in Energy Technology, W. S. Lyon,

ed., Elsevier, Amsterdam, 63“6 8 ( 1984).

Watters, R. L., Jr., "Progress in Instrumental Analysis: Developments in

Atomic-Absorption, X-ray Fluorescence, and Plasma-Emission Spectrometry

for the Analysis of Metals and Ores," Proc. of Mintek 50, Johannesburg,

RSA , March ( 1984) .

Wise, S. A., Fitzpatrick, K. A., Harrison, S. H., and Zeisler, R., "Operation

of the U.S. Pilot National Environmental Specimen Bank Program," in

Environmental Specimen Banking and Monitoring as Related to Banking, R.

A. Lewis, N. Stein, and C. W. Lewis, eds., Martinus Nijhoff Publishers,

Boston, MA, 108-129 (1984).

Zeisler, R. and Wise, S. A., "Quality Assurance and Protocols in Sample

Preparation of Biological Samples," in Biological Reference Materials,

W. R. Wolfe, ed., John Wiley and Sons, New York, NY, 257*280 (1984).

46
Zeisler, R., Harrison, S. H., and Wise, S. A., "Analysis of Human Liver

Specimens in the U.S. Pilot National Environmental Specimen Bank

Program," in Environmental Specimen Banking and Monitoring as Related to

Banking, R. A. Lewis, N. Stein, and C. W. Lewis, eds., Martinus Nijhoff

Publishers, Boston, MA, 331“351 (1984).

Zeisler, R., Harrison, S. H., and Wise, S. A., "Trace Elements in Human

Livers Using Quality Control in the Complete Analytical Process," Biol.

Trace Element Res., 6, 31“49 (1984).

3arnes, I. L., Brill, R. H., Deal, E. C., and Piercy, G. V. , "Lead Isotope

Studies of Some of the Finds from the Serce Liman Shipwreck," Proc.

1934 Symposium on Archaeometry, J. S. Olin and M. J. Blackman, eds.,

Smithsonian Institution, Washington, DC, in press.

Barnes, I. L. , Deal, E. , Chase, W. T., Homes, L. , Meyers, P., and Sayre, E. 4 V., "The Nine Tripods and the Six Formulas: Lead and Lead Isotope

Ratios in Ancient Chinese Bronzes," Proc. 1984 Symposium on Archaeometry, J. S. Olin and M. J. Blackman, eds., Smithsonian Institution,

Washington, DC, in press.

Burke, R. W., Mavrodineanu , R., and Smith, M. V. , "Standard Reference

Materials for Verifying the Accuracy of Spectrophotometers," American

Clinical Products Review and American Laboratory, in press.

Clark, C. W., Fassett, J. D., Lucatorto, T. B. , and Moore, L. J. , "Enhancement of the Isotopic Abundance Sensitivity of Mass Spectrometry by

Doppler-Free Resonance Ionization," Proc. of 2nd International RIS

Symposium, in press.

De 3ievre, ?. J. , Gallet, M., Holden, N. E. , and Barnes, I. L. , "Isotopic

Abundances and Atomic Weights of the Elements," J. Phys. Chem. Ref.

Data, V3, in press.

Fassett, J. D., Powell, L. J., and Moore, L. J., "The Determination of Iron

in Serum and Water by Resonance Ionization Isotope Dilution Mass

Spectrometry," in press.

Fassett, J. D., Travis, J. C., and Moore, L. J., "Thermal Atomization Sources

and Resonance Ionization Mass Spectrometry (RIMS)," Proc. of the

SPIE Symposium East ’84, in press.

Greenberg, R. R., "Radiochemical Procedures Used for Improved Low-Level

Determinations of Critical Elements in Biological Materials,"

Atomkernenergie-Kerntechnik , in press.

Greenberg, R. R. and Carpenter, B. S. , "High Accuracy/High Precision Determination of U-235 in Nondestructive Assay Standards by Gamma-Ray Spectrometry," Proc. Fifth Inti. Conf. on Nucler Methods in Environmental and

Energy Research, in press.

Greenberg, R. R., Fleming, R. F. , and Zeisler, R. , "High Sensitivity Neutron

Activation Analysis of Biological/Environmental Standard Referer.:-

Materials," Environ. International, in press.

47
Kelly, W. R., "On the Precise and Accurate Determination of the 24lpu Half-Life by Mass Spectrometry in press.

Kelly, W. R. and Paulsen, P. J., "Precise and Accurate Determination of High

Concentrations of Sulfur by Isotope Dilution Thermal Ionization Mass

Spectrometry," in press.

Kelly, W. R. and Paulsen, P. J., "Determination of Sulfur in NBS Coals by

Isotope Dilution Thermal Ionization Mass Spectrometry," in press.

Kingston, H. M. and Greenberg, R. R., "An Elemental Ratioing Technique for

Assessing Concentration Data from a Complex Water System," Environ.

International, in press.

Kingston, H. M., Paulsen, P. J., and Lambert, G. M., "The Determination of

Selenium and Tellurim in Stainless Steel, White Cast Iron, and Nickel

Base Alloy Standard Reference Materials by Isotope Dilution Spark

Source Mass Spectrometry , " Applied Spectroscopy, in press.

Koch, W. F. , Marinenko, G., and Wu, Y. C., "The Development of Reference

Materials for Acid Rain Research," Environ. International, in press.

Lutz, G. J., Rook, H. L. , and Lindstrcm, R. M., "Determination of 1-129 at

Natural Levels by Thermal Neutron Activation Analysis," Journal of

Trace and Microprobe Techniques, in press.

May, J. C., Rains, T. C., Mainethal, E. J., Briddle, G. N. , and Progan, J.

J., "Survey of the Concentration of Eleven Metals in Vaccines, Allergenic Products, Toxides, Blood, Blood Products and Other Biological

Products," J. Biol. Stand., in press.

Moody, J. R., "New Developments in Laboratory Design in the U.S.A.," in

Design, Construction and Refurbishment of Laboratori es , R. Lees and A.

F. Smith, eds., Ellis Horwood and Sons, Chichester, UK, in press.

Moody, J. R., "Sampling, Storage, and Handling of Materials for Trace Element

Analysis," in Sample Preparation Technology - Volume 3» Zymark Corp.,

Hopkinton, MA, in press.

Moore, L. J., "Stable Isotope Measurements with Thermal and Resonance

Ionization Mass Spectr ometry , " ACS Advances in Chemistry Series, Stable

Isotopes in Nutrition, in press.

Moore, L. J., Kingston, H. M., Murphy, T. J. , "The Use of Isotope Dilution

Mass Spectrometry for the Certification of Standard Reference Materials," Environ. International, in press.

Powell, L. J. and Murphy, T. J., "The Determination of Atomic Weights at

NBS —The Case of Silver and Its Impact on the Faraday," Chem. Tech., in

press

Pratt, K. W., "Chronoamperometri c Determination of Diffusion Layer Thick- nesses at Hydrodynamic Electrodes," Anal. Chem., in press.
Rains, T. C., Watters, R. L. , Jr., and Epstein, M. S. , "Application of Atomic

Absorption and Plasma Emission Spectrometry for Environmental

Analysis," Environ. International, in press.

Stone, S. F. and Zeisler, R. L. , "Evaluation of Biological Samples for

Specimen Banking and Biomonitoring by Nuclear Methods," Proc. of Fifth

International Conference on Nuclear Methods in Environmental and Energy

Research, April 2-6, in press.

Wise, S. A. and Zeisler, R., "The Pilot Environmental Specimen Bank Program,"

Environ. Sci. Technol . , in press.

Downing, R. G., Fleming, R. F., Maki , J. T. , Simons, D. S. , and Stallard, B. R., "Near-Surface and Interfacial Profiling by Neutron Depth Profiling

( NDP ) and Secondary Ion Mass Spectrometry (SIMS) ," Thin Solid Films,

submitted for publication.

Downing, R. G., Maki, J. T. , and Fleming, R. F. , "Application of Neutron

Depth Profiling to Microelectroni c Materials Processing," Special

Proceedings of the Industrial Chemical Division Session for the 187th

National Meeting of the American Chemical Society, L. A. Casper, ed . , submitted for publication

Marinenko, G. and Koch, W. F. , "A Critical Review of Measurement Practices

for the Determination of pH and Acidity of Atmospheric Precipitation,"

Environ. International, submitted for publication.

Moore, L. J., Fassett, J. D., and Travis, J. C., "Systematics of Multielement

Analysis Using Resonance Ionization Mass Spectrometry and Thermal

Atomization," submitted for publication.

Riley, J. E. , Jr., Mitchell, J. W., Downing, R. G., Fleming, R. F. , Lindstrom, R. M., and Vincent, D. M., "Materials Analysis Using Thermal

Neutron Reactions: Applications," Journal of Solid State Chemistry,

submitted for publication.

Tanaka, T. , Marinenko, G., and Koch, W. F. , "Further Developments in the

High-Precision Coulometric Titration of Uranium," submitted for publication.

Wilson, S. R., Paulson, W. M., Gregory, R. B. , Krause, S. J. Cresset, J. D.,

McDaniel, F. D., and Downing, R. G., "Properties of Ion Implanted

Polysilicon Layers Subjected to Rapid Thermal Annealing," Journal of

the Electrochemical Society, submitted for publication.

Wu, Y. C., Koch, W. F., and Marinenko, G., "A Special Report on the State of

the NBS pH Standards," Anal. Chem. , submitted for publication.
2 . Talks

Fassett, J. D., Travis, J. C., and Moore, L. J., "Resonance Ioni zation Mass

Spectrometry of Iron—Quantitative Aspects," 26th Ann. Conf. on Analytical Chemistry in Energy Technology, Knoxville, TN, October 4, 1983.

Invited

Kelly, W. R., "Enriched Rare Earth Isotopes as Tracers of Aerosol Particulate

Emissions from Coal-Fired Power Plants," Electric Power Research

Institute, Palo Alto, CA, October 4, 1983.

Koch, W. F., "Measurement of pH: Liquid Junction Potentials," U.S. Environmental Protection Agency, Research Triangle Park, NC , October 1 2, 1983.

Invited

Watters, R. L. , Jr., Norris, J. A., Small, J. A., McKenzie, R. L. andDeVoe,

J. R., "Material Transport in Atomic Spectrometry ," 26th Conference on Analytical Chemistry in Energy Technology, Knoxville, TN, October 12,

1983.

Fleming, R. F., "Elemental Depth Profiling with a Thermal Neutron Beam,"

Department of Chemistry seminar, University of Maryland, College Park,

MD, October 14, 1983-

Fassett, J. D., "Recent Developments in Resonance Ionization Mass Spectrometry," Washington Area Mass Spectrometry Discussion Group, October 1 7

,

1983- Invited

Fleming, R. F., Langland, J. K., and Downing, R. G., "Elemental Depth

Profiling with a Thermal Neutron Beam," Conference on the Use and

Development of Small and Medium Power Reactors, Cambridge, MA, October

17, 1983.

Greenberg, R. R. , "Radiochemical Procedures for Improved Low-Level Determination of Critical Elements in Biological Materials," International

Symposium on the Use and Development of Low and Medium Flux Research

Reactors, Cambridge, MA, October 17, 1983.

Rains, T. C., "State of the Art of Atomic Absorption Spectrometry ," 3rd

NBS-ADABSE Analytical Chemistry Workshop, National Bureau of Standards , Gai thersbur g , MD , October 25, 1983.

Watters, R. L., Jr., "Atomic Emission Spectrometry Using the Inductively

Coupled Plasma (ICP) Technique," 3rd NBS-ADABSE Analytical Chemistry

Workshop, National Bureau of Standards, Gaithersburg, MD, October 25,

1983. Invited

Gramlich, J. W., "Inorganic Mass Spectrometry Applications," 3rd NBS-ADABSE

Analytical Chemistry Workshop , National Bureau of Standards, Gaithersburg, MD , October 27, 1983. Invited

Deal, E. C., "Determining the Provenance on Works of Art and Comparative

Samples by Lead Isotopic Ratio Analysis," 3rd NBS-ADABSE Analytical

Chemistry Workshop, National Bureau of Standards, Gaithersburg, MD

,

October 28, 1983. Invited

50
Burke, R. W., "Standardization of Spectrophotometers and Spectrofluorometers," American Association for Clinical Chemistry, Michigan Section,

Pontiac, MI, November 3, 1983- Invited

Stone, S. F., "Trace Multi elemental Analysis of Banked Biological Samples,"

Analytical , Nuclear and Environmental Chemistry Division, University of

Maryland, College Park, MD, November 5, 1983.

Gramlich, J. W., "Determination of Atomic Weights at NBS," 883rd Meeting of

the Chemical Society of Washington, National Bureau of Standards,

Gaithersburg, MD , November 10, 1983. Invited

Downing, R. G., Maki, J. T. , Fleming, R. F., Stallard, B. R., and Simons, D.

S., "Near-surf ace and Interfacial Profiling by Neutron Depth Profiling

(NDP) and Secondary Ion Mass Spectroscopy (SIMS)," Thin Films and

Interfaces Symposium, Materials Research Society, Boston, MA, November

14, 1 983.

Fleming, R. F., "Neutron Depth Profiling for Materials Analysis," Department

of Nuclear Engineering seminar, University of Maryland, College Park,

MD , November 17, 1983

Olin, J. S. , Balckman, M. J., and Jornet, A., "Elemental Analysis of SpanishColonial Majolica to Determine Provenience," Seventeenth Annual Meeting

of the Society for Historical Archaeology, Williamsburg, V A, January 5,

1 984.

Barnes, I. L. and Deal, E. C., "The Use of Lead Isotope Ratios for the

Determination of the Provenience of Ancient Objects," Conservation

Analytical Laboratory seminar, Smithsonian Institution, Suitland, MD , January 10, 1984. Invited

Kelly, W. R., "Enriched Rare Earth Isotopes as Tracers of Aerosol Particulate

Emissions from Coal-fired Power Plants," Department of Energy, Germantown, MD , January 12, 1984.

Travis, J. C., "Laser-Enhanced Ionization Spectrometry ," Department of

Chemistry seminar, The Catholic University of America, Washington, DC,

February 3, 1984.

Ehrstein, J. R., Downing, R. G., Stallard, B. R., Simons, D. S. , and Fleming,

R. F., "Comparison of Depth Profiling of B-1 0 in Silicon by Spreading

Resistance Profiling, Secondary Ion Mass Spectrometry , and Neutron

Depth Profiling," Third Sympoisum on Semiconductor Processing, Sa.n Jose, CA, February 10, 1984.

Moody, J. R., "Characterization of Fluoropolymers and Other Polymers for

Trace Element Contamination," E.I. Du Pont Co., Wilmington, r F

,

February 13. 1984. Invited

Watters, R. L. , Jr., "Recent Advances in Atomic Spectrometry and Vimanalysis," Society for Applied Spectroscopy, New York Section, Frr-uiry

14, 1984. Invited

51
Kelly, W. R., "Analytical Techniques for Sulfur Isotope Measurement," DOE

Workshop on Sulfur Isotopes in Environmental Studies, Department of

Energy, Germantown, MD , February 22, 1984. Invited

Rains, T. C., "Atomic Absorption and Emission Spectrometry," ACS Short

Course, IBM, Endicott, NJ, February 22-24, 1984.

Barnes, I. L., "Trace Element Analysis - State of the Art," Southeastern

Pennsylvania Section, American Chemical Society, Elizabethtown College,

Elizabethtown, PA, February 23, 1984. Invited

Kelly, W. R., "The Potential Use of Sulfur as a Tracer for Field Experiments," Working Group for the Atmospheric Field Experiment, Council on Environmental Quality, Washington, DC, February 29, 1984. Invited

Norris, J. A. and Reed, W. P., "NBS Standard Reference Materials for the

Metals Industries: Current Activities and Future Trends," Pittsburgh

Conference, Atlantic City, NJ, March 1 984.

Moody, J. R., "Low Cost Alternatives in Clean Lab Design," Clinical Laboratory Seminar, Cleveland Clinic Foundation, Cleveland, OH, March 2,

1984. Invited

Rains, T. C., "Atomic Absorption and Plasma Emission Spectrometry," ACS Short

Course, Pittsburgh Conference, Atlantic City, NJ, March 2-4, 1 984.

Zhang, Z. K., "Determination of Germanium in Biological Fluids Using Electrothermal Atomization Atomic Absorption Spectrometry ," Pittsburgh Conference, Atlantic City, NJ, March 8, 1984.

Fleming, R. F. , "Nuclear Depth Profiling—Applications in Material Science,

Metallurgy and Semiconductor Devices," Departments of Nuclear Engineering and Materials Science seminar, University of Virginia, Charlottesville, VA, March 19, 1984.

Kelly, W. R., "Use of Isotopes as Tracers for Atmospheric Environmental

Problems," Inorganic Analytical Research Division Seminar, National

Bureau of Standards, Gai thersburg , MD , March 20, 1984.

Spielmann, K. S. and Blackman, M. J., "Trace Element Variability within an Outcrop: Smoky Hills Jasper from Collyer, Kansas," Second Conference

on Prehistoric Chart Exploitation, Carbondale, IL, March 20, 1984.

Deal, E. C., "Archaeometry, A New Approach to Old Porblems - Determining the

Provenance on Works of Art and Comparative Samples by Lead Isotopic

Ratio Analysis," University of the District of Columbia, Chemistry

Department, Washington, DC, March 21 , 1984. Invited

Fleming, R. F. , "Neutron Depth Profiling at NBS," ONR Meeting on Chemical

Instrumentation and Analysis, Midway, UT, March 24, 1984.

Barnes, I. L. , "Trace Element Analysis - State of the Art," Dallas-Ft. Worth

Section, American Chemical Society, Southern Methodist University,

Dallas, TX, March 26, 1984. Invited

52
Barnes, I. L. , ’’Trace Element Analysis - State of the Art,” Heart o' Texas

Section, American Chemical Society, Baylor University, Waco, TX , March

27, 1984. Invited

Barnes, I. L. , "Trace Element Analysis - State of the Art," Central Texas

Section, American Chemical Society, Texas Air Control Board, Austin,

TX, March 28, 1984. Invited

Barnes, I. L., "Trace Element Analysis - State of the Art," San Antonio

Section, American Chemical Society, University of Texas-San Antonio,

San Antonio, TX, March 29, 1984. Invited

Watters, R. L., Jr., "Progress in Instrumental Analysis: Developments in

Atomi c-Absorption , X-ray Fluorescence, and Plasma-Emission Spectrometry

for the Analysis of Metals and Ores," Mintek 50 International

Conference on Recent Advances in Mineral Science and Technology,

Johannesburg, RSA, March 30, 1984. Invited

Greenberg, R. R., Fleming, R. F., and Lindstrom, R. M., "Elemental Characterization of Four Coal Standard Reference Materials Via Instrumental

Neutron Activation Analysis and Prompt Gamma-Ray Activation Analysis,"

Fifth International Conference on Nuclear Methods in Environmental and

Energy Research, Mayaguez, PR, April 4, 1984.

Rains, T. C., "Atomic Absorption Spectrometry ," Elms College, Chicopee, MA,

April 4, 1984. Invited

Rains, T. C., "Sample Preparation - State of the Art," Elms College,

Chicopee, MA, April 4, 1984. Invited

Barnes, I. L. and Morales, P. , "Understanding Stray Magnetic Fields,"

Inorganic Analytical Research Division Seminar, National 3ureau of

Standards, Gai thersburg , MD , April 5, 1984.

Greenberg, R. R. and Carpenter, B. S. , "High Accuracy/High Precision Determination of U-235 in Nondstructi ve Assay Standards by Gamma-Ray Spectrometry," Fifth International Conference on Nuclear Methods in

Environmental and Eneregy Research, Mayaguez, PR, April 5, 1 984.

Watters, R. L. , Jr., "Improving Accuracy in Atomic Spectrometry and Microanalysis," CSIR, Pretoria, RSA, April 5, 1984. Invited

Zeisler, R. and Stone, S. F., "Evaluation of Biological Samples for Spec:".-”.

Banking and Biomonitoring by Nuclear Methods," 5th Conference on Nuclear

Methods in Environment and Energy Technology, Mayaguez, PR, April 6,

1984.

Lindstrom, R. M., "Neutron Activation Analysis of Semiconductor Materials,"

ACS Meeting, St. Louis, MO, April 11, 1984. Invited .

Downing, R. G., Maki, J. T. , and Fleming R. F. , "Application of Neutron

Profiling to Microelectroni c Materials Processing," Nation,: -. A

~ Meeting, St. Louis, MO, April 8, 1984. Invited

53
Travis, J. C., Fassett, J. D. and Moore, L. J. , "A Survey of Elements

Detected Using RIMS with Thermal Vaporization," Second International

Conference on Resonance Ionization Spectroscopy and Its Applications,

Knoxville, TN, April 18, 1984.

Koch, W. F. , "Ion Chromatography," Society for Applied Spectroscopy Professional Development Program, Gaithersburg, MD , April 23, 1984. Invited

Fassett, J. D., Travis, J. C., and Moore, L. J., "Thermal Atomization Sources

And Resonance Ionization Mass Spectrometry (RIMS)," SPIE Symposium East

’84, Arlington, VA, May 3, 1984. Invited

Koch, W. F., "Review of Current Practices in the Measurement of pH in Acid

Rain: Recommendations for the Future," Fourth Annual National

Symposium on Recent Advances in Pollutant Monitoring of Ambient Air and

Stationary Sources, Raleigh, NC, May 10, 1984.

Barnes, I. L., Brill, R. H. , Deal, E. C., and Piercy, V. G., "Lead Isotope

Studies of Some of the Finds from the Serce Liman Shipwreck," Symposium

on Archaeometry , National Museum of Natural History, Smithsonian

Institution, Washington, DC, May 14, 1984. Invited

Deal, E. C., "Determining the Provenance on Works of Art and Comparative

Samples by Lead Isotopic Ratio Analysis," International Archaeometry

Symposium, Washington, DC, May 15, 1984. Invited

Blackman, M. J., Olin, J. S. , and Jornet, A., "The Use of Interlaboratory

Data Sets in Provenience Studies," 1984 International Symposium on Archaeometry, Washington, DC, May 17, 1984.

Jornet, A., Blackman, M. J. , Westley, H. , and Olin, J. S. , "Study of Maiolica

from Three Production Areas of Spain," 1984 International Symposium on Archaeometry , Washington, DC, May 17, 1984

Olin, C. H., Cheng, Y., Blackman, M. J., and Olin, J. S. , "Neutron Induced

Autoradiography: A Novelty or a Useful Tool," American Institute of

Conservation Annual Meeting, Los Angeles, CA, May 18, 1984.

Rains, T. C., "State of the Art of Sample Preparation for Atomic Absorption

and Emission Spectrometry ," Rio Grande Section of Society for Applied

Spectroscopy , Albuquerque, NM, May 18, 1984. Invited

Kelly, W. R., "Application of Stable Isotope Tracers to Air Pollution

Problems," Symposium on Simple Approaches to Complex Environmental

Problems, ACS Middle Atlantic Regional Meeting, Newark, NJ, May 21,

1984. Invited

Kelly, W. R. and Ondov, J. M., "The Use of Enriched Isotopes of Rare Earth

Elements as Tracers of Aerosol," U.S.-DOE Workshop on Atmospheric

Tracers, Sante Fe, NM, May 22, 1984. Invited

Kelly, W. R., "The Use of Stable Sulfur Isotopes to Trace SC^, -" U.S.-DOE

Workshop on Atmospheric Tracers , Sante Fe, NM, May 23, 1984. Invited

54
Barnes, I. L. , "Recent Advances in Mass Spectrometry," U.S. Geological Survey

seminar, Reston, VA, May 25, 1984. Invited

Cacic, C. G., Crawford, D. W. , Machlan, L. A., "The Production and Provisional Certification of an Equal Atom Plutonium Isotopic Standard,"

32nd Annual Conference on Mass Spectrometry and Allied Topics, San

Antonio, TX, May 27“June 2, 1984.

Powell, L. J., Fassett, J. D. f and Moore, L. J. , "Resonance Ionization

Isotope Dilution Mass Spectrometry of Iron," American Society for Mass

Spectrometry , San Antonio, TX, May 30, 1984.

Diamondstone , 3. I., "Standard Reference Materials - Their Importance for

Transferring Technology," Department of Commerce Orientation Program,

Washington, DC, June 19, 1984.

Marinenko, G., "Proposed Electrochemical Primary Reference Methods for

Ionized Calcium," American Association for Clinical Chemistry,

Washington, DC, July 31 , 1 984.

Norris, J. A., "Qualitative and Semi-Quantitative Emission Spectroscopy,"

Modern Industrial Spectroscopy Course, Arizona State University, Tempe,

AZ, August 6-17, 1984.

Rains, T. C., "Atomic Absorption and Plasma Emission Spectrometry ," ACS Short

Course, Metropolitan State College, Denver, CO, August 8-10, 1984.

Zeisler, R. , "An Analytical Approach to the Accurate Determination of Trace

Substances in Biological Matrices," International Conference on Analytical Chemistry in Development, Colombo, Sri lanka, August 24, 1984.

Invited

Travis, J. C., Turk, G. C., and Schenck, P. K., "Ultrasensi ti ve Optcgalvanic

Spectroscopy , " 1984 Annual American Chemical Society Meeting, Philadelphia, PA, August 28, 1984.

Pratt, K. W. and Koch, W. F., "Determination of Trace-Level Cr(VI) in the

Presence of Cr(III) and Fe(III) by Voltammetric Flow-Injection Analysis

Without Prior Separation," 188th National Meeting of the American

Chemical Society, Philadelphia, PA, August 29, 1984.

Lindstrom, R. M., "Analytical Neutron-Capture Gamma-Ray Spectroscopy: Status

and Prospects," 5th Intern. Symposium on Capture Gamma-Ray Spectroscopy

and Related Topics, Knoxville, TN, September 1 0, 1984. Invited

Travis, J. C., Turk, G. C., and Epstein, M. S. , "Laser Induced Atomic

Fluorescence in Flames with 5 kHz Pulsed Excitation," Federation of

Analytical Chemistry and Spectroscopy Societies, Philadelphia, PA,

September 16-21, 1984.

55
Beary, E. S. , Paulsen, P. J., Lambert, G. M., '’Determination of Selenium in

Biological and Botanical Standard Reference Material's by SSMS Isotope

Dilution,” 11th Annual Meeting of the Federation of Analytical

Chemistry and Spectroscopy Societies, Philadelphia, PA, September 17,

1984.

Zhang, Z. K., "Trace Determination of Antemonty in Refractory Materials by

Atomic Absorption Spectrometry," 11th Federation of Analytical

Chemistry and Spectroscopy Societies Meeting, Philadelphia, PA,

September 18, 1984.

Greenberg, R. R., "Determination of Ultratrace Elements in Biological

Materials by Neutron Activation Analysis," 11th Annual Meeting of the

Federation of Analytical Chemistry and Spectroscopy Societies,

Philadelphia, PA, September 19, 1984. Invited

Rains, T. C., "Sample Preparation Workshop," 11th Annual Meeting of the

Federation of Analytical Chemistry and Spectroscopy Societies, Philadelphia, PA, September 19, 1984.

Moody, J. R. and Lindstrom, R. M., "The Selection of Apparatus and Containers

for Trace Element Analysis of Biological Materials," 11th Annual

Meeting of the Federation of Analytical Chemistry and Spectroscopy

Societies, Philadelphia, PA, September 19, 1984.

Epstein, M. S. , "Atomic Spectroscopy in the Certification of Reference

Materials for Environmental Analysis," 11th Annual Meeting of the

Federation of Analytical Chemistry and Spectroscopy Societies, Philadelphia, PA, September 20, 1 984.

Turk, G. C., Watters, R. L. , Jr., and DeVoe, J. R. , "Resonant Laser-Induced

Ionization of Atcms in an Inductively Coupled Plasma," 11th Annual

Meeting of the Federation of Analytical Chemistry and Spectroscopy

Societies, Philadelphia, PA, September 20, 1984.

Watters, R. L. Jr., and Zhang, Y. K., "The Effects of Various Solvents on ICP

Analysis of Oils," 11th Annual Meeting of the Federation of Analytical

Chemistry and Spectroscopy Societies, Philadelphia, PA, September 20,

1 984.

Zeisler, R., "Analytical Procedures for the Accurate Determination of Trace

Substances in Biological Media," XIX Yugoslav Meeting on Nuclear

Medicine, Zadar, Yugoslavia, September 25~29, 1984. Invited

Committee Assignments

I. Lynus Barnes

Member, Department of Health, Education, and Welfare, The Chemistry

Task Force of the National Shellfish Sanitation Program

Washington Editorial Review Board

International Union of Pure and Applied Chemistry, Commission of

Atomic Weights and Isotopic Abundances

Chairman, IUPAC , Commission on Atomic Weights and Isotopic Abundances,

Working Group on Statistics Applied to Atomic Weights

56
Robert W. Burke

Member, ASTM E-03, Chemical Analysis of Metals

ASTM D-3*J, Standards for Waste Characterization

Barry I. Diamonds tone

Member, ASTM D-34, Waste Disposal

ASTM D-3^.02.01, Section on Batch Extractions

ASTM E-03, Chemical Analysis of Metals

ASTM E-03.01 , Gases in Metals

ASTM E -03.93, Long Range Planning

Chairman, Task Force on Oxygen in Metals

Michael S. Epstein

Member, ASTM D-19, Water

Editorial Advisory Board, Progress in Analytical Atomic

Spectroscopy

Treasurer, National Society for Applied Spectroscopy

Chairman, Baltimor e-Washington Section of the Society for Applied

Spectroscopy

Delegate, FACSS Governing Board for the Division of Analytical

Chemistry of the American Chemical Society

Ronald F. Fleming

Member, ASTM E-10.05, Nuclear Radiation Metrology

Organization Committee, Sixth Symposium on X- and Gamma-Ray

Sources and Applications

John W. Gramlich

Member, Institute of Nuclear Materials Management Committee NT 5.9.3,

Non-Destructive Assay (Physical Methods)

Robert R. Greenberg

Member, NBS Chemistry Storeroom Committee

Trace Analysis Committee, Biomedical Division, American

Nuclear Society

Howard M. Kingston

Member, ASTM C-26.05, Methods of Test

ASTM C-26.07, Waste Materials

Task Group Leader, C-26.05, Leachate Analysis Methods

Congressional Science Fellow, Energy and Commerce Committee

Science and Technology Committee

William F. Koch

Member, ASTM D-19, Water

ASTM D-19. 02, General Specifications and Technical Resour oec ASTM D-19.05, Inorganic Constituents in Water

ASTM D-22, Air

John K. Langland

Chairman, NBS Electronics Storeroom Committee

Richard M. Lindstrom

Alternate Member, NBSR Safety Evaluation Committee

57
Lawrence A. Machlan

Member, ASTM 026, Nuclear Fuel Cycles

ASTM 026.05, Test Methods

Secretary, ASTM 026.01, Editorial and Terminology

George Marinenko

Member, ASTM D-19, Water

Chairman, D-1 9.05.04.03, Voltammetry

D-19. 09. 06, Redox Potentials in Saline Water

D-1 9.09.07 , pH in Saline Water and Brines

D-19. 09. 01, Chlorine Residuals in Saline Water

Councilor, National Capital Section of the Electrochemical Society

John R. Moody

Member, ASTM D-19, Water

ASTM D-19. 05, Inorganic Constituents in Water

Audit Committee, Chemical Society of Washington

Contamination Control Standards and Practices for Federal

Standard 209c, Institute for Environmental Sciences

Delegate, Society for Applied Spectroscopy

Representative, FACSS Governing Board

Thomas J. Murphy

Member, American Chemical Society Committee on Analytical Reagents

American Chemical Society Committee on Membership Affairs

International Union of Pure and Applied Chemistry (IUPAC),

Commission on Atomic Weights and Isotopic Abundances

International Union of Pure and Applied Chemistry (IUPAC),

Subcommittee for the Assessment of Isotopic Abundances

Commission on Atomic Weights and Isotopic Aundances

Chairman, American Chemical Society Admissions Committee

Audit Committee, Chemical Society of Washington

Councilor, Chemical Society of Washington

John A . Norri

Member, ASTM E-02, Emission Spectroscopy

ASTM E-02. 01 , ASTM E-02. 02,

ASTM E-02. 04,

ASTM E-02. 05,

ASTM E-02. 06,

ASTM E-02. 07,

ASTM E-02. 08,

ASTM E-02. 09,

ASTM E-02. 1 3,

Fundamental Practices

Statistics

Sampling and Standards

Copper, Cobalt, Nickel, and High Temperature

Lead, Tin, Zinc

Aluminum

Refractory Metals

Ferrous

Terminology

Lura J. Powell

Member, Chemical Society of Washington

Board of Directors, NBS Child Care Association

Chairman, Committee on Isotope Ratio Measur ements , American Society

for Mass Spectrometry

Treasurer, Chemical Society of Washington

President, Standards Committee for Women

58
Theodore C. Rains

Member, Proposal Evaluation Committee for National Science Foundation

Editorial Board of Annual Reports on Analytical Atomic

Spectroscopy (The Chemical Society of London) and the

Canadian Journal of spectroscopy

Subcommittee No. 6 on Methods of Air Sampling and Analysis

ASTM E-02.10, Non-Metallic Materials

ASTM E~02.13, Nomenclature

ASTM D-01 , Paint and Related Coatings

ASTM D-19, Water

Chairman, FACSS Governing Board

Prof ess or- in- charge , ACS Short Course on "Atomic Absorption and Plasma

Emission Spectroscopy"

Task Force Leader, Scientific Instrumentation Information Network and

Curricula (SUNG) for project on "Atomic Absorption

Spctroscopy"

Column Editor, Journal of Applied Spectroscopy

Ronald W. Shideler

Member, NBS Electronics Storeroom Committee

Yung-Chi Wu

Member, ASTM D-19, Water

Rolf L. Zeisler

Member, NBSR Safety Evaluation Committee

Chairman, Trace Element Analysis Committee, Technical Group for Biology

and Medicine, American Nuclear Society

4. Other

a. Seminars

November 8, 1983 * Mr. Richard J. Walker, Department of Earth

and Space Sciences, State University of

New York at Stony Brook, Stony Brook, New

York, "Petrogenesis of the Tin Mountain

Pegmatites ."

February 16, 1984 - Dr. Kenneth W. Pratt, Jr., Research

Chemist, Electroanalytical Chemistry

Group, Inorganic Analytical Research

Division, National Bureau of Standards,

Gaithersburg, MD , "Electrochemical

Flow-Injection Analysis Using Vibrating

Electrodes ."

April 12, 1984 - Dr. Marcel De Bruin, Interuni versi tair

Reactor Instituut, The Netherlands,

"Identification of Sources of Heavy

Air Pollution Using Multielement Analys:.'

of Aerosol Samples and Biological Ind:

tors: Possibilities and Limitations."

59
May 3, 1984

June 1 1

,

June 21 ,

August 1

b.

November

Dr. Judith R. Turnlund, Project Leader,

Nutrients Research Units, United States

Department of Agriculture, Berkeley,

California, "Stable Isotopes of Trace

Elements: New Tools for Human Nutrition

Research ."

1984 - Dr. Philip J. Savickas, Department of

Chemistry, University of Virginia, "New

Ionization Methods in Glow Discharge Mass

Spectrometry ."

1984 - Dr. Kenneth R. Thompson, Nuclear Data,

Inc., Schaumburg, Illinois, "High-Speed

Data Acquisition and Loss-Free Counting in

Energy Spectroscopy."

, 1984 - Professor C. Th. J. Alkemade, University

of Utrecht, Holland, "Distortions of

Saturation Curves in Laser-Induced Atomic

Fluorescence ."

Conferences Sponsored

1 1-1 6, 1984 - R. Zeisler, ANS-ENS International

Conference: Special Sessions on Standardization of Collection and Preparation of

Biomedical Samples for Trace Element

Analysis, Washington, DC.

60
III. Organic Analytical Research Division

Willie E. May, Chief

Dennis J. Reeder, Deputy Chief

A. Division Overview

The Organic Analytical Research Division conducts research to develop

and improve techniques for the preparation, purification, characterization,

and analysis of organic compounds and uses these techniques in the solution

of analytical problems related to national needs. The Division's research is

carried out by five groups that are organized along functional lines:

Bioanalytical Techniques, Electrochemistry, Gas Chromatography, Liquid

Chromatography and Mass Spectrometry. As in the past, the Division has been

actively engaged in the application of organic analytical chemistry to

measurement problems related to energy, the environment, health and clincial

chemistry, and food and nutrition. Results of the Division's research

activities are utilized by industry, other Federal Agencies, public and

private institutions and associations, and other research programs at the

National Bureau of Standards. Research efforts during the past year have

resulted in the publication of more than 50 articles in books and archival

journals

As in past years, our research efforts have primarily been in basic

organic analytical chemistry, in support of other Federal agency requests and

to a limited degree, in short-term projects performed on a service analysis

basis. Substantial progress has been made in the chromatography program and

in each of the Division's three Competence Building Programs; Organic

Electrochemistry, Analyses of Ionization Mechanisms and Ion Structures in

Organic Mass Spectrometry, and Bioanalytical Techniques - The Use of Proteins

in Analytical Chemistry. Accomplishments in these areas will be discussed in

the Group Overviews and Technical Reports that follow. As in the past, the

major portion of our Other Agency support has come from the Environmental

Protection Agency (EPA), the Department of Energy (DoE), and the Food and

Drug Administration (FDA).

During the past year, our efforts included: providing three reference

materials and analyses to establish NBS traceability on a number of calibration materials and proficiency testing samples to EPA; continuing to function

as a reference laboratory for a network of DoE supported laboratories

involved in the analysis of polar organics in energy related samples; critically evaluating methods used for the analysis of ethylene oxide on surgicial

tools for FDA; performing analyses in support of other NBS programs such as surveying the types and amounts of chlorinated compounds given off from the

burning of refuse derived fuels, identifying daughter products of combust i cr. that can be used as markers for the occurrence of arson, and service analyses

performed for the Office of Standard Reference Materials, e.g., ethyl er.- dibromide in wheat flour and stability of several SRM's previously certified.

We have continued our collaborative efforts with the Gas an

Particulate Science and the Inorganic Analytical Research Divisions in * Bioanalytical Competence and Toxic Organics in Air Programs. Our collate'-

tion with the Gas and Particulate Science Division has led to the devel':r~---r*

of an isotope dilution gas chromatography/mass spectrometri c method !:r :

61
determination of toxic organic compounds in air at concentrations ranging

from a few parts-per-billion (ppb) to 10 parts-per-million (ppm). This

method will be used at NBS in the certification of multicomponent toxic

organics in air standards. A sample transfer device developed as part of

this program along with the appropriate gas standards will be used by EPA to

determine compound specific detection limits and sensitivities for GC/MS

systems. Additional details concerning this program are given in Technical

Report 3, page 76. In our collaborative effort with the Inorganic Analytical

Research Division, we have used neutron activation analyses to investigate

metal/protein interactions and in elucidating the mechanisms responsible for

protein visualization after silver staining (see Technical Report 7, page

80).

A considerable effort has continued to be devoted towards supporting

the NBS Standard Reference Materials Program. Analytical measurements for

the Certification of SRM 1614 (2,3,7,8-TCDD in Toluene), SRM 1 6-43 > (GC/MS

Performance Evaluation Standard), SRM 1821 A (Ethanol in Water) and Creatinine

in SRM 909 (Human Serum), have been completed. We have initiated measurements on SRM’s 41C (Dextrose), 1650 (Diesel Particulate Matter), and 1587

(Nitro-PAH in Methanol). This year a major effort was directed toward the

development of methods to be used in the certification of future SRM’s.

Methods development began or continued on the determination of triglycerides

in human serum, selected chlorinated pesticides and PCB’s in cod-liver oil,

dioxins in soils, and fat and water soluble vitamins in dry milk powder.

Our research programs in liquid chromatography and organic mass spectrometry were bolstered by the addition of a second NRC postdoctoral

fellow in each of these areas. We were also successful in obtaining a postdoctoral research fellow for our Gas Chromatography Group. Dr. Kwokei Ng,

a Research Associate supported by the College of American Pathologists left

NBS in July, to accept a permanent industrial position. His replacement

represents an immediate hiring priority. Dr’s. Gary Byrd and Lane Sander

will complete their two year postdoctoral terms October 1, 1984, but will

remain with us in our Mass Spectrometry and Liquid Chromatography Groups,

respectively. The acquisition of a biochemist with experience in enzyme

immobilization techniques and procedures, and an electrochemist with

expertise in the area of chemically modified electrodes continue to be of

high priority.

In the coming year, we anticipate that our efforts will continue to be

directed towards basic research to maintain and improve our measurement

capabilities in each of our five groups (see Group Overviews for specifics),

providing analytical support for problems of national importance, development

of reference materials for specific sponsors, and certification of Standard

Reference Materials. We expect to maintain support for our three Competence

building programs and have requested support for another in ’’High Resolution

Chromatography". We will expand our role as a National Reference Laboratory

for trace organic chemical measurements to include a network of laboratories

that are measuring blood serum levels of selected vitamins as part of the

National Cancer Institute's Chemoprevention Program. We have been requested

to develop "Drugs of Abuse in Urine" ref erence materials for use in the

Department of Defense’s Drug Screening Program and to develop confirmatory

method for Chemical Warfare Agent BZ in blood and urine by the U. S. Army

Medical Bioengineering Research and Development' Laboratory. Finally, a joint

proposal with the Center for Radiation Research, to identify unique compounds

62
resulting from food irradiation processing for possible use as chemical

dosimeters, has been submitted to the Department of Health and Human

Services

1 . Bioanaly tical Techniques Group; Overview

The Bioanalytical Techniques Group has concentrated efforts in several

areas that are broadly interrelated with research goals focused on (1)

development of separation methods that are applicable to biotechnology, (2)

high- accuracy determination of analytes of interest to the clinical community, and (3) maintenance of expertise and performance research in high-field

nuclear magnetic resonance spectroscopy. These three areas of research

reflect the directions that the group is taking. The biotechnology and

spectrometry areas have been generally funded by the competence building

program and the clinical work has been supported by STHS funding from the

Office of Standard Reference Materials.

In work designed to further our understanding of biomolecule

separations, we have continued to perform research in two-dimensional

electrophoresis, thin-layer isoelectric focusing, and metal- ion affinity

chromatography. Two-dimensional electrophoresis has been used to assess the

usefulness of currently-available protein ’’markers" for molecular weight

standardization and isoelectric focusing definition. While there are many

available materials being used by laboratories to standardize electrop'noreti

systems, recent studies by our group have shown that marker proteins that are useful in one electrophoretic system may not be adequate for other systems. A critical evaluation of such standards has been an on-going project at N3S

during the past year. Thin-layer isoelectric focusing (TLIEF) is being used

as the prime analytical tool for identifying protein fractions from column

chromatography experiments. In collaboration with several groups from the

National Oceanographic and Atmospheric Administration (NOAA) , we are using

TLIEF to develop methods for the identification of several closely related

fish species. We have also developed, in conjunction with a NCAA guestworker, procedures for staining enzymes directly on thin-layer gels for

assessment of genetic differences in squid species. Our work with metal-ion

affinity chromatography has been extended to examine the behavior of selected

enzymes on column supports to which various metals have been covalently

bound. This work, directed toward understanding the role of the metal ion in

binding proteins, should help in designing reagents, in developing purification techniques, and in producing new media for separating biomolecules.

Our work and interest in electrophoresis as a separation and identification technique led to our co-sponsoring with the Electrophoresi s Society of

the Americas, and hosting of a workshop in June, 198*4 on "Electrophores i

Standardization: Approaches and Needs". The 5*4 attendees included leade-s

from various scientific sectors: fifteen industrial representatives; eight

from universities; and the remainder from government agencies, including

state crime laboratories, the National Aeronautical and Space Administration,

National Institutes of Health, Uniformed Services University of the Health

Sciences, and the Food and Drug Administration. Talks on various approach^

to standardization in many areas of electrophoresis were presented. 3e?::n

of the success of this workshop, NBS has been asked to addresn

electrophoresis standardization issues at a national meeting of t.- •

63
Electrophoresis Society and to coordinate an international interlaboratory

comparison study involving the electrophoretic separation of a standard

mixture of proteins.

Work has continued vigorously in organic analysis by NMR spectroscopy.

Due to the complexity of the NMR spectra of biomolecules, there is a great

need to exploit and develop methods that permit selective separation of NMR

parameters and allow differentiation of structural types. For these reasons,

we are extending our competence in the application of two-dimensional NMR

methods to problems of bio-organic significance. We are also investigating

the broader application of recently developed polarization transfer methods

for NMR spectroscopy of liquids and of spectrum editing methods for structure

elucidation. Improvements in NMR sensitivity are extremely important in

trace organic analysis. Polarization transfer methods offer the possibility

of such improvements for the NMR of heteronuclei via two major mechanisms:

(1) signal: noise improvement proportional to the ratio of the magnetogyric

constants of the proton and the heteronucleus being observed, and (2)

dependence of the polarization transfer experiment relaxation properties on the relaxation times of the protons which are generally shorter than those of

the heteronuclei. It is now believed that the efficiency, and hence the

sensitivity and spectrum editing accuracy of polarization transfer experiments, is dependent on using short radiofrequency pulse widths for the

excitation of samples. This can be a problem for the large sample tube sizes

that are of prime interest for analysis of biological samples. Therefore, we

are taking steps to upgrade the NMR pulse sequences to minimize the RF

heating (and hence degradation) of polar solutions of biomolecules.

The NMR projects pursued this year include detection and measurement of

the aldehydo forms of aldoses, measurement of the lactose content of the

dried milk SRM 15^9, investigation of the tautomerism of food dyes by 1 5 n NMR, work on the structure of a growth hormone, 1 3C NMR of bovine serum

albumin, two-dimensional J-resolved and proton-proton chemical shift corre- lated NMR of the angiotensin SRM 998, and complete assignment of the proton

and 1 3c NMR spectra of four equilibrium anomers of digitoxose by two-dimensional proton-proton , and proton-carbon chemical shift correlation techniques, respectively.

Development of methods based on isotope dilution for the definitive

quantification of analytes in human serum has continued in collaboration with

the Mass Spectrometry Group. This past year, we concentrated efforts in

refining the synthesis of labeled materials used in the ID/MS determination

of creatinine. Work has also continued in the preparation of a labeled

tripalmitin for use in the development of a triglyceride definitive method.

We have continued to perform analyses that are related to the Standard

Reference Materials Program. This past year we have undertaken analyses

leading to the characterization and certification of renewal SRM Hlb,

Dextrose. Extensive polarimetry studies have been made on this material.

Homogeneity testing and structure confirmation have been performed by

high-field proton NMR. The anomeric contents and purity of the dextrose were examined by both 1 3c and proton NMR since two independent analytical methods

are required for SRM certified values.
Construction of the triple-module modernized laboratory for biotechnology is scheduled for the last quarter of FY8M. This facility should

relieve some of the congestion and improve efficiency in performing electrophoretic and chromatographic separations.

During the second year of the competence building program in the

bioanalytical area, our staff size has remained stable, with the loss of

several part-time personnel and the addition of a chemist who was retrained

to perform electrophoretic separations. The search for a biochemist as an addition to the staff is still continuing. Several candidates have been

interviewed and have given seminars. Two of the most promising prospects

declined our offers and took other positions. There is intense competition

with industrial biotechnology firms for highly qualified biochemists.

Under the guidance of Dr. P. V. Sundaram, Max Planck Institute for

Experimental Medicine, Goettingen, Germany, we are beginning work on enzyme

immobilization. During the last part of FY84, Dr. Sundaram will conduct a three-week hands-on workshop designed to transfer enzyme immobilization

techniques to our staff. The ability to stabilize biomolecules by immobilization will assist us in developing new analytical reagents. This area of

research is of prime importance in our development of procedures and standards for separation, identification and quantitation of biomolecules.

In FY85 we will continue to focus our efforts on improving our electrophoretic separation capabilities, applying neutron activation analysis to

enhance our understanding of the mechanisms involved in protein staining and

the nature of metal-protein interactions; and on defining the role of

electrophoretic material purity on reproducibility of electrophoretic

separations. In addition, we will continue our efforts in developing

high-accuracy methods for analytes of importance in clinical chemistry, and

in improving our NMR spectroscopy capabilities. We will expand our efforts

in enzyme immobilization and develop techniques to examine glycoproteins and

other large biomolecules. Research in the food/ nutrition area will expand as coordination efforts with other laboratories involved in the National Cancer

Institute Chemoprevention Program project is begun.

Dennis J.. Reeder, Group Leader; Lyle A. Alexander, Alex Cohen, Bruce Coxon,

Alexander J. Fatiadi, Diane K. Hancock, Cindy L. Hsu, Millard Maienthal,

Kristy L. Richie, Robert Schaffer

2. Electrochemistry Group: Overview

A continuing need exists for the development of new approaches for

trace organic and organometal analyses. Until recently, electrochemical

techniques have not been widely used for such analyses because of their lack

of resolution. The combination of chromatography with electrochemical

detection and the advent of electrocatalysis at polymer-modified electrodes

have provided new impetus for novel approaches in the analysis of organic

compounds

Our research efforts have continued to be focused on the study of

organic and organometallic redox reactions using state-of-the-art electrochemical techniques: cyclic voltammetry, chronoamperometry , chronocc./. - metry , and rotating ring-disk electrochemistry; hybrid techniques, suer, ar spectroelectrochemistry and liquid chromatography with electrocr.er. : v.

65
detection; the preparation and evaluation of chemically modified electrodes;

and mathematical modeling of electrochemical processes in support of the

Group research activities.

In the organic electrochemistry competence building program we have

continued to make good progress toward our research objectives and have

applied these results to NBS programmatic needs. We have demonstrated the

power and versatility of liquid chromatography with electrochemical detection

( LCEC) for organometal speciation and biochemical analyses. Most successful

to date has been the development of novel electrochemical detectors for

chromatographic analysis. Multiple electrode designs and various excitation

waveforms have resulted in significant advances in selectivity and sensitivity. In addition, we have pioneered the use of reductive electrochemistry

which has greatly extended the applicability of this method of detection. For

example, a new method was developed for the determination of nitro-PAHs using

nonlinear gradient elution chr omatography in combination with computercontrolled, potential-optimized, differential-pulse detection. Spectroelectrochemistry , both uv-visible and surface-enhanced Raman, has provided

considerable useful information on reaction mechanisms and the molecular

species adsorbed at the electrode surface. These studies have included the

characterization of the electrochemical behavior of a series of transition

metal dithio-oxocarbon complexes and the identification and fate of pyridine

species at a silver electrode surface. The most premising area of research

in terms of both understanding fundamental processes at electrode surfaces

and providing a novel class of chemical sensors is that of the chemical

modification of metal, semiconductor, and carbon electrodes. Problems

associated with polymer-film stability and loss of activity of the electrocatalytic redox centers are being overcome and highly selective and sensitive

analytical devices are expected to be feasible soon.

While the uv-visible transmittance approach will continue to be used to

aid in the elucidation of redox mechanisms, Raman spectroscopy will be

replaced by Fourier-transf orm infrared (FTIR) spectroscopy which provides

similar in-situ capabilities but is not limited by electrode substrate

material or analyte structure. This latter technique will allow us to probe

interfacial and polymer-film phenomena which profoundly affect electrochemical behavior.

In the area of LCEC, our plans call for continued research to enhance

the sensitivity of this technique by the development of microarray electrodes

to increase the signal-to-noi se ratio and the use of chemically modified

electrode detectors to provide increased analyte specificity.

LCEC and polymei—modified electrocatalyti c electrodes are potentially

applicable to a diversity of analytical problems of considerable clinical,

environmental, and military importance. Consequently, our goal is to extend

the applicability of electrochemical sensors through a combination of

fundamental research on the design of novel electrodes and on the electrode

reaction mechanisms of organic analytes. Through this research, we expect to

provide leadership in trace organic electroanalysis and a basic understanding

of the electrochemical phenomena that can lead to state-of-the-art analytical

methods and standards. Thus, the development of electrocatalyti c sensors

will be a major research thrust in the group because of their potential as novel analytical devices of high selectivity and sensitivity. Our mathematical models of the charge transport processes within the polymer films are

66
being refined and will provide new insights into optimal designs for this

type of electrocatalyti c sensor. The development of these sensors will not

be limited to inorganic metal-complex catalysts but will be extended to enzymatic and immunological reactions via immobilized enzymes and antibodies

confined to the electrode surface. The use of sensitive marker compounds

encapsulated in synthetic biomembranes (liposomes and vesicles) which rupture

when contacted by specific analytes, e.g., antigens or other types of

biocomponents, also are feasible using electrode modification procedures. It

is expected that biotechnological approaches will become more widely used

based on their high reaction specificity and which, when combined with the

sensitivity of electrochemical methods, will lead to unique classes of

analytical sensors.

Our staffing level has remained stable and most of the major pieces of

equipment acquired in past years are now operational. To expand our research

efforts into the area of biotechnology, e.g., bioelectrochemical sensors,

immunoelectrochemistry , etc., it would be desirable to increase our staffing

to include a scientist knowledgeable in both biochemistry and electrochemistry . While the automation of selected instrumentation is progressing as planned, we are still in need of a versatile, rapid-scanning spectrophotometer and are collaborating with scientists at Ohio State University in the

design and construction of a state-of-the-art instrument. In addition, we

will require additional general purpose instrumentation, such as computercontrolled electrochemical systems, for the anticipated arrival of another

graduate cc-op student (R. Kannuck, Univ. of Md . ) and a part-time guest

worker (H. Blount, NSF). Also, new liquid chromatogeni c equipment (pump,

gradient mixer, data acquisition system, ADC, and computer software) is

needed to maintain our competence in this area.

Richard A. Durst, Group Leader; Elmo A. 31ubaugh, William A. MacCrehan,

Gwendolyn S. Marbury, Scott R. Mund, Janet Sevy, William T. Yap

3. Gas Chromatography Group: Overview

The Gas Chromatography (GC) Group uses state-of-the-art chromatographic

techniques to analyze for trace organic components of environmental, clinical, and consumer samples. The Group’s goals are multifold. Primarily, we seek to maintain competence by updating our chr omatographic capabilities

through research in basic chromatographic science. An example of this is the

effort to expand into the field’s of multidimensional and supercri tical fluid

chromatographies. Secondarily, the group seeks to promote trace organic

Standard Reference Materials (SRM’s) by proposing new SRM's and increasing

the number of certified compounds in existing SRM’s by additional

chromatographic analysis.

We are undertaking a cooperative program dealing with the kinetics and

recovery of PCDD in soils and marine sediments with scientists at the

University of Maryland. Through this program, we hope to attain a working

knowledge of how chlorinated compounds interact with environmental matrices

and thus to design optimal procedures for their analysis. We are also

engaged in a joint investigation with scientists in the Center for Material

Science (CMS) on the feasibility of combining microspectrof luori me: r; detection with capillary supercritical fluid chr omatography (SFC'.

detector developed in CMS, is capable of excitation beam focus at di

of 50 pm to yield an extremely high flux density which should (;

67
compatible with SFC and might be sensitive enough to detect polycyclicaromatic hydrocarbons in normal gas chr omatographi c effluents. A spectroflourimetric detector may find considerable application in iscmer specific

analyses. The research into the identification of pollutant sources through

gas chromatographic analysis of remotely collected air samples is approaching

a successful conclusion. Two unique marker compounds, retene and levoglucosane, have been identified and are being used for sample-source correlation.

During the past year we have expended major efforts in laboratory

computerization and developing data handling algorithms (see Technical Report

11, page 83). Research directed towards SRM production was carried out on

the determination of (1) polychlorinated biphenyls and pesticides in codliver oil, (2) 2, 3. 7, 8-tetrachlorodi benzdioxin in soils, (3) polychlorinated

biphenyls in human blood serum, (4) dinitro-pyrenes in a simple solvent

matrix, and (5) polycyclicarcmatic hydrocarbons in marine bivalves (freezedried mussels )

The GC Group has participated in a number of Other Agency funded

projects. We worked with FDA on the determination of residual ethylene oxide

in polymeric medical devices, with the Law Enforcement Standards Laboratory

on the determination of arson accelerants, with EPA to establish traceability

for their performance standards and to develop a PCB’s in human serum

reference material.

Research during the coming year will be concentrated in several

distinct areas. First we shall study the thermodynamics and kinetics of the

multiple-column separation process. Second, in order to be able to predict

solute retention behavior, we will continue our studies on separations of

complex congeneric mixtures with particular emphasis on the mechanisms of

solute/matrix interactions and congeneric specific identification. Third, in

support of the new National Cancer Institute chemoprevention program, we will

investigate gas chromatographic methods for the analyses of vitamins A, C,

and E.

The Group needs an additional four-channel, microprocess or -based

integrator and a mi crocanputer for data management. A mass-selective GC

detector is needed in the ultra-trace, isomer specific work, such as analysis

of dioxins and furans in soils and polycyclicaromatic hydrocarbons in animal

tissue.

The Group’s personnel has had an overall increase due to the addition

of one permanent staff member and one postdoctoral fellow. The two new members are Michelle M. Miller and Howard T. Mayfield. Ms. Miller is a Ph.D

candidate at Georgetown University doing thesis research on the thermodynamics and kinetics of the chromatographic separation process. Dr.

Mayfield is a NRC Post-Doctoral Fellow and will be investigating the basic

aspects of multidimensional GC with particular emphasis on the theoretical

prediction of solute retention. His work should lead to the ability to

non-empiri cally choose the best combinations of gas chromatographic columns

and temperature conditions for any separation of closely eluting solute

pairs. Mr. Delmo P. Enagonio has retired this year, but is returning as a part-time, rehired annuitant. In addition to these staff changes, we have

68
two guest workers fran the People’s Republic of China who are spending a year

with us to gain state-of-the-art proficiency in analytical capillary gas

chromatography.

Stephen N . Chesler, Group Leader; Delmo D. Enagonio, Hui-Xiang Gu, Franklin

R. Guenther, Hui-Cong Liu, Howard T. Mayfield, Michele M. Miller, Reenie M.

Parris, Richard E. Rebbert

4. Liquid Chromatography Group: Overview

The major activities of the Liquid Chr omatography (LC) Group are directed towards ( 1 ) gaining a better understanding of the chemical and

physical processes that contribute to retention and selectivity in LC and (2)

applying this information to the development of methods for the isolation,

separation, identification, and quantification of specific solutes in both

simple and complex mixtures.

Research in understanding retention mechanisms has centered on the

influence of both the stationary phase and the mobile phase on the retention

process. Studies of stationary phase effects have continued to focus on the

unusual properties of polymeric C-jg phases in comparison to the more conventional monomeric C -j s phases. Recent efforts in these studies have evaluated

the influence of silica substrate characteristi cs on the column selectivity

of the resulting bonded phase. Monomeric and polymeric C -j 3 bonced phases were prepared on 22 different silica substrates with pore diameters ranging

from 50-1000 A and the resulting bonded phases were characteri zed chemically

(i.e., percent carbon) and chromatographically . Significant changes in

selectivity, as well as absolute retention were observed as a function of

pore size, with the greatest changes observed for the polymeric C -j 3 phases.

The effect of silica pretreatment on the bonded phase synthesis and column

selectivity was also examined. A model for the polymeric phase synthesis has

been proposed where the extent of the reaction (i.e., degree of polymeric

character) is limited by a size exclusion mechanism, hence the differences in

behavior of phases prepared on different size pores.

These studies have provided an understanding of the essential factors

required to produce C-jg phases capable of separating isomeric polycyclic

aromatic hydrocarbons (PAH). An interesting separation on a polymeric C 1

column of 12 PAH isomers of molecular weight 278, with an elution order that

correlates closely with the shape of the PAH solute, illustrates the high

selectivity of these phases for resolution of such isomers. Future work in

the study of stationary phase effects will attempt to characterize the unique

features of the polymeric C

3 phase (e.g., physical topography and solutestationary phase interactions) that produce this selectivity.

Research on the role of the mobile phase on selectivity in LC has be**'-, initiated by Dr. Joe P. Foley, a NBS/NRC Postdoctoral Fellow from the

University of Florida. Dr. Foley has investigated the optimization of

selectivity in isocratic reversed-phase LC via control of secondary chemical

equilibrium (SCE). Computer simulations of data were used as guides in th** derivation of new equations to predict the optimum conditions for the separation of specific solutes. These theories were then verified with - -.* separation of monofunctional acids and bases on C 1

columns using pH : . r i' • • aqueous mobile phases. In the coming year, this approach will b<* u- • :

* expand the investigation from isocratic to gradient elution systems.

69
In the area of supercritical fluid chromatography (SFC), an instrument

for use in SFC with a carbon dioxide mobile phase on packed LC columns was obtained and made operational. Preliminary evaluations of the analytical

capabilities and uses are currently in progress. Investigations of the

retention mechanisms of SFC, in particular as compared to conventional LC, are planned for the coming year. The potential of SFC for accurate

quantitative analysis will be evaluated and compared to more conventional

chromatographic techniques.

During the past year, LC methods have been developed and are being

applied to the certification of two environmentally significant SRM’s: SRM

1650 ’’Diesel Particulate Matter” and SRM 1587 "Nitrated Polycyclic Aromatic

Hydrocarbons in Solvent”. For the analysis of the diesel particulate matter,

normal-phase LC is used to isolate the PAH into two fractions (PAH with 16 or les3 aromatic carbon atoms and those with 1 8 to 24 aromatic carbon atoms). A total of 12 PAH will be determined in these two fractions by using reversedphase LC with fluorescence detection. SRM 1587 "Nitrated Polycyclic Aromatic

Hydrocarbons in Solvent” will consist of several mixtures of mono- and

dinitro-PAH. The LC methods developed will separate the specific nitro-PAH

in the SRM (i.e., six mononitro-PAH and three dini tropyrenes )

The LC Group continues to be involved in the measurement of environmentally important substances. Multidimensional LC/LC and LC/GC approaches

were used in the analysis of a coal tar sample to identify and quantify the

PAH in this complex matrix. A series of performance evaluation samples,

prepared for EPA by an outside contractor, was analyzed using LC with two

different detection methods (uv-absorption and post-column deri vatization

with fluorescence) as part of their quality assurance process. Reversed-phase

and normal-phase retention data for about 70 polychlorinated biphenyl (PCB)

congeners have been obtained as part of an effort to evaluate the feasibility

of using LC, in addition to GC, to quantify PCB’s in the proposed cod-liver

oil SRM.

In conjunction with the Mass Spectrometry Group, research in the use of mass spectrometry (MS) as an LC detector has continued. In the past, LC-MS

has been used to quantify individual organic compounds in complex mixtures

(e.g., phenol and cresols in shale oil). However, interef erences frequently

occurred. The additional selectivity of a triple quadrupole MS with

colli sionally activated dissociation has been used to overcome this problem.

Using this approach, dibenzothiophene was determined in a coal liquid and a crude oil sample. The analysis required no sample pretreatment and had a detection limit of 20 ng. In fact, the selectivity of MS-MS almost renders

the LC separation unnecessary. Future work will center on analytical

applications to exploit the potential of LC-MS -MS.

Two guest workers in the LC group have been involved in studies related

to environmental measur ements . Dr. Jan T. Andersson, a guest worker from the

University of Ulm, Federal Republic of Germany, is investigating the use of

LC to separate polycyclic aromatic sulfones [produced as the oxidation

products of polycyclic aromatic sulfur heterocycles (PASH)] as part of a project to isolate and measure PASH in environmental samples. Dr. Azza Aziz

Moustafa, from the Cairo University in Egypt and sponsored by an AMIDEAST

Peace Fellowship, joined the LC group in September and is involved in the

measurement of pollutants in environmental samples.

70
Future efforts related to the analysis of environmental samples will

involve the determination of more "polar" compounds (e.g., hydroxyl-, nitre-*-

,

and, cyano-substi tuted polycyclic aromatic compounds and polycyclic aromatic

ketones and quinones) . These types of compounds (often containing more than one polar f unct tonality) have been tentatively identified in air and diesel

particulate samples in the "moderately polar and polar" fractions (generally

isolated by classical column chromatography) which have been found to have

significant mutagenic activity. However, the determination of these com- pounds presents a formidable task since they are relatively non-volatile and

few authentic standards are available. LC offers the greatest potential for

isolation and separation of these compound types.

In the area of food and nutrition measurements, work has continued in

LC methods development for selected water- and fat-soluble vitamins in a non-fat dry milk powder (SRM 1549) and an infant formula material. Concentration values for ascorbic acid were obtained for SRM 1549; however, levels

of the fat-soluble vitamins of interest in this sample were relatively low.

As a result, an infant formula matrix, which contains higher levels of

vitamins D 2 and A, has been used in the development of methods for the

determination of fat-soluble vitamins in a milk matrix. An LC method was also used for the determination of lactose in SRM 1549 and results compared

favorably with those obtained by NMR.

LC methods were developed and employed for the measurement of solutes

of clinical and nutritional significance. The three isomeric forms of

bilirubin (denoted 9a, 3a, and. 13a) are all present in SRM 916 "Bilirubin";

however, this material is certified only for total bilirubin. These isomers

are readily separated by LC, but quantitation by uv detection is difficult

since each isomer has a different uv molar absorptivity. The molar absorptivity of each isomer was determined and this information was used to

calculate the isomeric content of SRM 916 . With the initiation of a new program to provide quality assurance standards for the National Cancer

Institute in the measurement of selected vitamins in human serum, our efforts

in the nutrition area will expand in the coming year. As part of this

program LC methods will be developed and evaluated for the measurement of

vitamin C (ascorbic acid), vitamin A (retinol), vitamin E ( a-tocopherol ) , and

a- and fi^carotene in human serum.

Stephen A. Wise, Group Leader; Jan T. Andersson, Bruce A. Benner, Jeanice M.

Brown-Thomas , Nicole C. Chessick, Richard G. Christensen, Joe P. Foley,

Walter F. Kline, Sam A. Margolis, Azza A. M. Moustafa, Lane C. Sander, John

P. Sullivan, and Karen D. Timmons.

5. Mass Spectrometry Group: Overview

The Mass Spectrometry Group has undertaken research in several areas involving both basic and applied research. The major continuing efforts have

been directed to the development of mass spectrometri c methods for the

accurate quantification of individual compounds in complex mixtures, the

development of an isotope dilution method for hazardous chemicals in gazer a* the ppb level, and to the laser induced photodissociation of ions and t collision induced dissociation of ions as part of the competence bull:.--'

71
program in mass spectrometry , "Analysis of Ionization Mechanisms and Ion

Structures". A number of the specific results of these efforts are included

in the Technical Reports Section.

The quantitative measurements made are concentrated in the

environmental and clinical areas. Measurements of chemical compounds in

environmentally important materials have generally been of small molecules at

low levels (ppm to ppb) for the purpose of providing SRM's or reference

materials for other agencies. High-resolution capillary column gas chrcmatography/mass spectrometry with selected ion monitoring has provided the

selectivity and sensitivity necessary for quantification of individual

organic compound species in these complex samples. The need for specific

measurements has been one of the driving forces behind an ongoing investigation of negative ion chemical ionization mass spectrometry. The initial

results of these investigations were reported last year. Those results plus

recent findings will appear in Analytical Chemistry , and are summarized in

Technical Report 2, page 75.

We plan to continue the ongoing studies with which the group is

involved with special attention to further investigation of the underlying

mechanisms and utility of negative ion chemical ionization.

As part of a joint project with the Gas and Particulate Science

Division for the EPA on research leading to standards for hazardous chemicals, the Mass Spectrometry and Gas Chromatography groups are developing a method for measuring toxic organic compounds in gases at the ppb to ppm

level. The results are summarized in Technical Report 3, Page 76. The

method will provide EPA with a direct way to determine the sensitivity of a GC/MS system and NBS with an independent method for certifying the

concentrations of organic compounds present at low levels in gases.

The clinically related efforts, conducted in collaboration with the

Bioanalytical Techniques Group, have centered on the development of definitive methods based on isotope dilution and gas chromatography for the

quantification of human serum constituents. A Human Serum Standard Reference

Material, SRM 909, was released in 1980 and now has values certified for the

organic analytes cholesterol, glucose, uric acid, urea, and creatinine. The

methodology developed for determination of urea has recently been published

in Analytical Chemistry and that for creatinine appears in Technical Report

1, page 7^ with publication planned for the latter part of this year. The

methods developed for the certification and stability testing of the Human

Serum SRM have also been used to place values on analytes in serum pools

supplied by the Centers for Disease Control and in the serum pools distributed by the College of American Pathologists in their extensive laboratory surveys. During the coming year, we intend to develop a definitive

method for triglycerides and provide a certified value for SRM 909.

The competence building program in mass spectrometry , "Analysis of

Ionization Mechanisms and Ion Structures", was begun in October 1 980. Two of

the several activities included are in the Mass Spectrometry group. One of

these involves laser induced metastable ion generation as a selective probe

for molecular structure. The wavelength dependent photodissociation of ions

created by electron impact was observed for a variety of molecules and this

year one of the major milestones of the program, the observation of the

photodissociation of ions generated by soft ionization techniques, was

72
achieved. The results are presented in Technical Report page 76. One of

the significant disadvantages of the soft ionization techniques is the lack

of molecular structure information available. During the next year, we will

investigate the photodissociation of ions generated using a cesium ion gun to

see if photodissociaticn can be used to obtain that informat ion.

We have been fortunate to have Dr. Kwokei Ng with us for the past year

as the Roger K. Gilbert/Coliege of America Pathologists Fellow. Dr. Ng has

been responsible for the mass spectrometry part of the definitive methods

measurements. We are pleased to have Mrs. H. X. Gu and Mr. Y. Gao from the

People’s Republic of China involved in the activities of the Group.

Edward White V, Group Leader; Gary D. Byrd, Laurence R. Hilpert, Yuji Gao, H.

X. Gu, Stanley Meiselman, Daniel J. Pereles, Lorna T. Sniegoski , Michael J. Welch, Timothy J. Wozniak

-/

73
B. Selected Technical Papers

(Organic Analytical Research Division)

1. Development of a Definitive Method for Serum Creatinine (15320)

A. Cohen, K. Ng, R. Schaffer, M. J. Welch, and E. White V

The measurement of serum creatinine levels is an important and

frequently used test for renal function. As part of an on-going program to

develop definitive methods for organic analytes in serum, we have developed

an accurate and precise isotope dilution mass spectrometric method for serum creatinine. We have used this method to certify the concentration of

creatinine in SRM 909, a freeze"*dried human serum, and to assign definitive

values to serum pools used in a round"*robin evaluation of a reference method

and to College of American Pathologists Survey sera.

Briefly, the method consists of addition of a known weight of

creatinine^l 3C2 (synthesized at NBS) to a known weight of serum. After an overnight equilibration, the serum is put on a weak acid resin column to

separate creatinine from creatine. The creatinine is then derivatized with

2,4"*pentanedione , acetic acid, and ethanol to form the ethyl ester of

N"-(4, 6"*dimethyl"*2^pyrimidinyl )"*N~methylglycine

Samples are introduced into a low resolution, magnetic sector mass spectrometer via a gas chromatograph equipped with a non^polar glass capil"*

lary column. The magnetic field is switched between m/z 150 and 152, the

most abundant electron impact fragment ions for the unlabeled and labeled

forms of the creatinine derivative, respectively. The intensities measured

at each mass are summed separately across the GC peak and the sums are ratioed. For calibration, standards consisting of known amounts of unlabeled

and labeled creatinine derivatives are measured immediately before and after

each sample and are chosen such that their ratios bracket that of the sample.

Each sample is remeasured on a separate day with the order of standards

reversed

With proper care at each step, this method yields results of high

precision. For example, for the measurements of SRM 909, three sets consist"*

ing of six samples each were measured and found to have a relative standard

deviation of 0.18% for a single measurement. To prove accuracy is more difficult, but it is possible to demonstrate an absence of bias in the

measurement process. To do this we remeasured eight samples from the three

sets by two other methods: (1) using ammonia chemical ionization for

generation of (M+1) + ions for measurement; and (2) using a fused silica

column and another ion source for measurement of M

+ ions. The three differ"*

ent measurements gave mean results for the eight samples which differed by

less than 0.06J.

Manuscripts are in progress for definitive methods for creatinine and

uric acid. A paper describing the definitive method for serum urea appeared

in Analytical Chemistry , Vol . 56, pages 713^19, 1 98-4 , following earlier pub"-

lications for cholesterol and glucose definitive methods. Work is now in

progress on a definitive method for serum triglycerides.

74
2 . Investigation of Factors Affecting the Selectivity of Negative Ion

Chemical Ionization Mass Spectrometry for Isomeric Polynuclear Aromatic

Hydrocarbons (26108)

G. D. Byrd and L. R. Hilpert

Negative ion chemical ionization mass spectrometry has been shown to

give excellent selectivity for the detection of certain compounds in specific

classes of organic compounds, and high sensitivities for those compounds in

complex materials. We have observed the molecular anion of benzo (a )pyr ene

(BaP) to be more than 1000 times more abundant than that of its isomer

benzo (e ) pyrene (3eP) under certain ion source conditions using electron

capture negative ion chemical ionization [1], During the past year we have

studied the pressure and temperature dependence of the selectivity for

detection of BaP. The variation in the selectivity for detection of BaP to

BeP was measured as a function of ion source pressure over a range of source

pressures from 0.1 to 1.2 Torr (13-3 to 1 60 Pascal). The selectivity of

detection, defined as:

(Abundance of BaP molecular anion/ng BaP)

(Abundance of BeP molecular anion/ng BeP)

decreased by an order of magnitude in going from low to high pressure.

The absolute sensitivity for the detection of BaP was also measured as

a function of the ion source pressure. The absolute sensitivity for a species depends, in part, on the extent to which the newly formed and excited

molecular anions can be stabilized by interactions with reagent ga3 molecules

through the process of collisional stabilization. Collisons can also lead to

fragmentations, however, with a resulting decrease in the molecular anion

abundance and thus a decrease in sensitivity. The BaP signal (m/z 252) was a maximum at a pressure of 3.0 x 1 0" 14 Torr (0.04 Pascal) in the ion source

manifold and 0.45 Torr (60 Pascal) , in the source.

The variation in the selectivity of detection for BaP to BeP was also

measured as a function of the ion source temperature over a range of source

temperatures from 100 to 250 °C at a constant source pressure. As the source

temperature was increased from 100 to 200 °C , the abundance of the BaP mo- lecular anion increased relative to that for BeP, and the optimum selectivity

was observed at 2G0 °C . The absolute sensitivity for the detection of Ba? was also monitored as a function of source temperature and was a maximum at

approximately 150 °C.

The reasons for the increased production of BaP molecular anion over

that of BeP are still unclear and must await the results of additional

experiments. However, the analytical capability of negative ion chemical

ionization mass spectrometry is enhanced by our ability to change both the

selectivity of detection for BaP and the absolute sensitivity for detection

of BaP by carefully adjusting the ion source pressure and temperature.

[1] Hilpert, L. R., Byrd, G. D., and Vogt, C. R. Selectivity of Negative Ion

Chemical Ionization Mass Spectrometry for Benzo[a jpyrene , Anal. Cher

56 (11), 1842, 1984.

75
3 . Development of an Isotope Dilution GC/MS Procedure for Analysis of

Toxic Organics in Air Mixtures (15320) “

G. D. Byrd, S. N. Chesler, R. G. Christensen, L. T. Sniegoski, and E. White V

As part of an EPA project for the analysis of trace toxic organic

compounds in air, a method for cold-trapping of organic compounds at ppb

levels was developed. Analysis is by gas chromatography/ mass spectrometry

(GC/MS) with labeled compounds used as internal standards. The method serves

two purposes; a sensitivity check of a GC/MS system as a whole using an SRM

,

and as a second method for certification of trace level organics in gas

cylinder SRM’s. This method will be used for the analysis of toxic organic

compounds in air for EPA, and for the analysis of organic compounds in

compressed gases, such as nitrogen, for certification of SRM's.

The trap developed consists of a coil of stainless steel tubing and has

a low dead volume. A valve placed between the gas cylinder and the trap

controls the flow of gas through the trap, and a heated injection port on the

trap allows introduction of liquid samples for spiking. The coil is cooled

in dry ice-ethanol for trapping of organic compounds, which are later

desorbed by electrical heating. The desorbed material is injected onto the

GC column through a needle at the end of the coil.

Cylinders of brcmobenzene in nitrogen at levels of 25 ppb and 1 ppb

have been analyzed using this trap. The method consists of flushing bromobenzene through the warm trap and then trapping the bromobenzene by cooling

the trap in a bath of dry ice-ethanol while measuring the volume of gas

passed through the trap with a wet test meter. A spiking solution of

bromobenzene-d^ is added through the heated injection port, the mixture of

labeled and unlabeled compounds is desorbed into the GC/MS, and the ratios of

labeled to unlabeled brcmobenzene are measured. A cylinder previously

determined to be 25.3 ± 2.5 ppb by GC and gravimetric preparation in the

Inorganic Analytical Research Division was measured at 26.0 ± 2.0 ppb using

the GC/MS trapping method. Similarly, a cylinder determined as 1.3 ± 0.2 ppb

was measured at 1.53 ±0.15 ppb with our method. In both instances the error

bars overlap for the two values.

Now that the trapping method has been demonstrated to work satisfactorily with bromobenzene, a four- component mixture of benzene, toluene,

chlorobenzene, and bromobenzene in nitrogen at the 10 and 0.25 ppm levels

will be analyzed by the same method.

4. Photodissociation of Ions Generated by Soft Ionization Techniques

( 26108 )

D. J. Pereles, R. L. Sams, J. C. Travis, M. J. Welch, and E. White V

The soft ionization techniques, field ionization (FI), field desorption

(FD), and fast atom bombardment (FAB), are widely used to characterize

fragile molecules. Important structural information is often missing,

however, since little or no fragmentation is observed with the first two

techniques and the limited fragmentation observed with fast atom bombardment

is often obscured by other processes. To obtain this structural information,

energy must be added to the ion to induce fragmentation. This increase in

76
the internal energy of the ion can be accomplished by colliding the ion with

a neutral molecule or by absorption of one or more photons. Collision

induced dissociation has been widely used as a tool for structure determina-*

tion, but photodissociation has not, although it is potentially more select

tive since the energy can be more precisely controlled. The photodissociation

of ions has therefore been investigated as part of the mass spectrometry

competence building program to see if the technique might be useful for

obtaining structural information on molecules whose mass spectrometry

requires the use of soft ionization techniques.

A Mattauch^Herzog geometry mass spectrometer has been modified to

permit irradiation of ions in the first field-* free region by light from an argon ion laser, and the ions formed in the field^free region have been

studied using both accelerating voltage scans and linked magnetic field

electric sector voltage (3/E) scans.

The fragmentation of n^butyl benzene has been studied by a variety of

techniques and we have examined the photodissociation of n-* butyl benzene

generated by electron impact for comparison with earlier published results.

Our results for m/z 91/92 ratios versus photon energy ranged from 0.4 to 2.0

which is substantially lower than the previous results where ratios increased

from 1 to 7 over the same photon energy range. Our results were reproduce

ible, and independent of both the type of scan (B/E or accelerating voltage)

and laser beam path. They are in reasonable agreement with results from

charge exchange mass spectrometry measurements. The magnitude of the

difference in the results of the two photodissociation studies is not

understood. We have also examined the effect of a high power pulsed laser

and observed a strong dependence of the m/z 91/92 ratio on power, an effect

not observed with the argon ion laser and not predicted by the published

model. Although small molecules are not our main interest, we intend to

pursue the matter by investigating a more comprehensive model of the

processes occurring.

The particular experimental arrangement which we have constructed has

allowed us to demonstrate for the first time the photodissociation of ions

generated by soft ionization techniques, specifically field ionization and

field desorption. The photo*induced metastable transitions observed for

field ionized species include: for n^ butyl ben zen e , m/z 134+92 and 1 3

i4-*91 : for nitrobenzene, 123+77; and for 3,5-^dinitrobenzoi c acid, 212+166. This

last metastable transition was not observed in the absence of laser light.

The photo* induced metastable transitions observed for field desorbed species

include: for cresol^red, m/z 382+302; for Sudan IV, 380+223; and for methyl

red, 269+1^8. All of these transitions were also observed without laser

light, but were enhanced by up to 60 percent with laser light. The magnitude

of the methyl red transition was wavelength dependent. The parent ion in all cases where photodissociation was observed was M

+ *

Plans for the immediate future include: installation of a cesium ion

gun to provide a more intense and stable ion beam and to allow invest i ga* :: n of the photodissociation of the larger molecules to which FA3 provides

access; improvements in the laser beam^ion beam interaction; and mod.f: - tions of the data system required to allow the acquisition and signal

averaging of data from metastable scans. If the planned experiments d--"-

strate convincingly the potential of the photodissociation of ions as

77
technique for the determination of the structure of large organic molecules

as expected, a choice will be made among the several, very different

approaches to an analytically useful instrument.

5. Investigation of Ion/Molecule Reactions in a Triple Quadrupole Mass

Spectrometer (26108)

R. G. Christensen, E. White V, and T. J. Wozniak

Tandem mass spectrometers, and in particular triple quadrupole mass spectrometers , are becoming more widely available in analytical laboratories.

The most common use of the MS/MS technique is to look at collision-induced

dissociation of ions, a process in which ions selected by the first mass analyzer collide with target gas molecules while passing through the center

quadrupole, and the resulting fragment ions are scanned by the final quadrupole. The advantage over more conventional mass spectrometers is the added

selectivity made possible by the addition of a second mass analysis step. The

collision process also has the potential for considerable selectivity if the

collision gas is chosen to allow for more chemistry than simple dissociation

in the ion-molecule reaction occurring in the center quadrupole. Therefore,

it was decided to investigate the selectivity of formation of adduct ions.

Since it is generally not possible to discriminate between isomers of

polynuclear aromatic hydrocarbons by collision-induced dissociation, discrimination by adduct formation, if found, might be analytically useful.

A series of 3"*» and 5-ring PAH were tested, including several

isomer pairs. They were allowed to react at low collision energies with

various reagent gases, including hydrocarbons , water, nitrogen, and various

amines. Because of the design of the ion source, the ions have a range of

collision energies of approximately 0-3 V. For initial investigations, this

is thought to be an advantage, providing a wider range of conditions for

adduct formation.

Comparing the ion current for the parent with that for the adducts [M+A

yielding (M+A) +

, (M+A-1) +, etc.] showed relative adduct formation ranging

from several parts per thousand for some PAH, and up to sixty percent, in the case of a f luorene-pyri dine adduct. Differences between seme isomers were observed with some gases, but not with others. For example, water gives

about a 5^fold difference in adduct formation with anthracene and

phenanthrene , as does ammonia between benzo (a )pyrene and ben zo (e ) pyrene . It was noted that pyridine forms adducts very strongly with the PAH containing

5-membered rings.

Other areas to be investigated are the use of reactive target gases

such as acetylenes, and trials with compounds having heteroatoms, such as nitrogen-containing heterocyclic PAH.

78
6 . Analysis of the Proton and Carbon-13 NMR Spectra of Equilibrated

Digitoxose by Two-Dimensional, Chemical Shift Correlation Methods

(15320)

B. Coxon

In a previous report, [1], we described the development of a new radios

frequency pulse sequence for performing two-dimensional (2D) heteronuclear

J-resolved NMR spectroscopy with sensitivity enhancement by the DEPT

(Distortionless Enhancement by Polarization Transfer) method. A key feature

of this method is the ability to distinguish carbon-hydrogen groups of

differing multiplicities. For this reason, digitoxose (the carbohydrate

component of the cardiac glycosides digoxin and digitoxin) was selected as a model for demonstration of the method, since this sugar contains all three

types of car bon- hydrogen groups, namely CH , CH2, and CH3. During the course

of this work, we discovered that solutions of the single anomer B^D-digitoxopyranose in dimethylsulfoxide-dg equilibrate quite rapidly (2-3 days) to

give a mixture of five forms that have now been characterized and identified

by Ir and 1 3c NMR techniques as being two pyranoses, two f uranoses , and an open- chain aldehydo form.

Application of the 2D DEPT heteronuclear J-resolved 1 3c NMR technique

to the equilibrated mixture yielded the gross assignments for the CH, CH2,

and CH3 structural types for the four ring forms only because, at a concentration of 0.1%, the aldehydo form is beyond the dynamic range of the 2D NMR

methods used. The problem of assigning the complex methine carbon region

completely has been tackled by using a combination of 2D "'h— and 13c— ^H

chemical shift correlation methods. Complete 1 H NMR assignments for the

equilibrated mixture were first generated by application of 2D

'

1 H--'I H

chemical shift correlation, a technique that yields a 2D spectrum with 'H chemical shifts in both dimensions. The observation of off-diagonal "cross

peaks" indicates which protons are spin coupled to each other, and a spin

coupling connectivity pathway was traced through the 2D spectrum for each

ring form in turn. Assignment of the complex "*H NMR spectrum of the mixture

by conventional spin decoupling techniques would have required 40 separate

experiments. In this way, a complete set of "'h chemical shifts and almost

complete sets of CH and OH 1 H—"'H coupling constants were measured for the

four ring forms of digitoxose. Although digitoxose is a structural homolog

of 2-deoxy-D-ri bose , the 1 H—"’H coupling constants of the pyranoid forms of

digitoxose indicate that they exist in chair conformations different from

those of 2-deoxy-D-ri bose [2]. This difference is attributed to the

conformational locking effect of the methyl substituent in digitoxose.

With the "*H NMR assignments in hand, detailed 1 3c NMR assignments were

then made by 2D heteronuclear 1 3c— ^H chemical shift correlation, a process

that is mediated by the one-bond 1 3c— "'h coupling constants. For this work,

a new technique [3] was used that gives 1 H decoupling in both the ^ and

1 -1

dimensions. This method collapses most of the 1 H— ^ multiplets in the 2D

1 3c— 1 H chemical shift correlated 13c NMR spectrum, thus leading to sharper

peaks and increased sensitivity. For the four ring forms of digitoxose, ^11

of the vicinal 1 h—iH coupling constants were removed by this technique.

However, for the a-pyranose, B^pyranose, and ot-furanose forms that ha 7-

non-equivalent protons at C-2, the geminal couplings (Jp 2' ~ 14 Hz' betw<

these protons remained in the 2D 1 3c—— 1 H correlated spectra, thus affording

79
further useful selectivity. The H-2 and H-2' protons of the B^furanose form

are chemically equivalent and hence their geminal coupling constant did not

appear in the 2D 13c—

h correlated spectra.

The complete set of 13c chemical shift assignments obtained for the

four ring forms of digitcxose allowed the dependence of the shifts on ring

size to be ascertained. The four ring forms were also measured quantitatively by both 1 h and 13c NMR, and good agreement between the two methods was observed

[1] B. Coxon, in Technical Activities 1983, Center for Analytical

Chemistry, H. S. Hertz, R. A. Velapoldi, and J. K. Taylor, Eds., NBSIR

83^2786, p. 1 -49 ; see also B. Coxon, Abstracts 24th Experimental NMR

Conference, Asilomar, CA, April 10*14, 1 983.

[2] B. Coxon, J. Carbohydr. Chem. , special NMR issue, in press.

[3] A. Bax, J. Magn. Reson. , 53, 517 (1983).

7. Identification of Metal Binding Proteins in Polyacrylamide Gels by

Neutron Activation Studies (261 1 1

)

D. Hancock, D. Reeder, S. Stone, and R. Zeisler

Over the past two years, we have developed techniques for the

separation of complex protein mixtures using two-dimensional gel electrophoresis. The samples are separated into polypeptide maps which consist of

several hundred protein "spots" in a polyacrylamide matrix. The protein

spots are generally detected using non-specific protein stains such as Coomassie Blue or the more sensitive silver stain.

Identification of the individual spots remains a difficult problem. One

approach to this problem is to apply a detection method that is more discriminating than the general protein stains. Recently, we have begun to

apply neutron activation analysis techniques to polyacrylamide gels to

determine the feasibility of detecting specific metal-binding proteins as well as phosphoproteins . Our results show that two-dimensional electrophoresis gels can be prepared with a low background of metals, a prerequisite

for trace analyses. Metal-binding proteins such as carbonic anhydrase (which

usually binds zinc) are easily detectable although it appears that seme proteins may act as metal scavengers, accumulating an array of trace metals.

Neutron activation analysis is also being used on silver-stained gels

to gain mechanistic information on this widely-used, but rather ill-defined

and troublesome staining technique. This information will be used to

establish staining conditions on a more scientific basis than the empirical

approach presently used.

Future research with neutron activation techniques will address the

interrelationships between trace elements and biological macromolecules

during bioanalytical separations. Knowledge of the mechanisms of interactions may be gained by studying the _in vitro and _in vivo functions of the

trace elements in the macromolecules. These investigations may provide new tools for the specific qualitative and quantitative determinations of these

molecules in complex natural protein mixtures.

80
3. Squid Species Differentiated by Use of Thin Layer Isoelectric Focusing

(2611 1)

C. L. Hsu, D. J. Reeder, and K . L. Richie

During the past year, MBS has been involved in a collaborative effort

with scientists at the National Oceanic and Atmospheric Administration (NOAA)

in an attempt to differentiate squid species using thin layer isoelectric

focusing (TLIEF) . The market for squid is increasing in commercial importance and is rapidly becoming a growing area of export. Thus arises the need

by NOAA to assign a total allowable catch for squid so that expert quota can

be determined. However, to prevent overfishing of particular species of

squid, the different species must be identified. This problem is best

approached by using TLIEF which involves the separation of proteins in an electric field due to differences in their charge.

Squid were collected from the Pacific Ocean within a 1 000 mile radius

of Midway Islands by a NOAA researcher. The squid were subsequently classified according to their weight, length, and location when caught. Samples

were stored at -60 °C until analyzed. Sample preparation involved crushing

and grinding of frozen muscle tissue followed by extraction with an appropriate buffer until a slurry of tissue was obtained. The homogenized tissue

was centrifuged at 40,000 x g for 30 minutes at 4-6 °C. The supernatant was collected and scored frozen in 1 00 pL aliquots until needed.

The samples were analyzed by isoelectric focusing using thin (-300 ym)

polyacrylamide gels. Approximately one yL of sample was applied to the gels

and electrophoresed for 75 minutes, followed by silver staining for visualization of the protein. Samples were grouped in each run according to either

location or size of catch.

Our preliminary data have shown that it is possible to group the squid

protein patterns into at least four distinct types. Additionally, we have

observed at least two types of banding patterns with direct enzyme staining

for phosphogiuccmutase. These differences are now being correlated with the

observed biological descriptions, e.g., size, weight, presence of certain

marking patterns, etc. These results are expected to help NOAA scientists

determine squid species populations in different areas of the ocean. These

data then need to be correlated over time to ascertain whether there are local concentrations of certain squid species at particular times of the

year.

Future plans on this project will focus on additional enzyme studies

including quantitative measurements using laser densitometry to further

detect genetic differences.

9. Determination of Pesticides and PCBs in Cod-Liver Oil (15601)

S. N. Chesler, H. X. Gu, R. M. Parris, K. D. Timmons, and S. A. Wise

A commerically available cod-liver oil is being evaluated for use as a Standard Reference Material. Tissue specimens are often analyzed for p:lychlorinated biphenyl (PCB) and pesticide components. Cod-liver oil may t- useful surrogate for this matrix.

81
An analytical method has been developed for the determination of

pesticides and single PCB congener components in cod-^liver oil. The oil

sample is extracted and initially cleaned using a dimethylformamide/ water-*

hexane partitioning procedure. Semi^preparati ve liquid chr omatographic (LC)

fractionation of the extract yields fractions that are analyzed using high

resolution gas chr omatography with electron capture detection. An internal

standard method of quantification is employed.

Initially, we have targeted four pesticides and seven PCB components as analytes: hexachlorobenzene , 4,4’^DDT, 4,4' -^DDE, transnonachlor , and PCB

Nos. 44, 99, 153, 133, 180, 170, and 194. Multiple extractions, fractionations, and GC analyses have verified the reproducibility obtainable using the

procedure developed for these components. GC/MS analyses were used as a check of the identity of the pesticide components and to verify the number of

chlorine substituents of the PCB congeners. We are currently evaluating

additional compounds for use as internal standards in this procedure. This

material has been analyzed for dioxins by .chemists at the Dow Chemical

Research Laboratory.

To evaluate the feasibility of using LC as a second analytical method,

chromatographic retention data for 70 PCB congeners have been collected using

both reversed^phase (HP) and normal^phase (NP) LC. Neither RP^ nor NP^LC

showed sufficient selectivity to achieve the required resolution to quantify

individual congeners. The data are being evaluated to determine if a combination of the two chromatographic modes can be used to determine

selected congeners.

10. Determination of Dioxin in Soils (15601)

S. N. Chesler and R. M. Parris

Analysis of soils for tetrachlorodi benzo^p-^dioxins (TCDDs) and tetra^

chlorodi benzof urans (TCDFs) and of complex matrices, in general, for low ng/g

to pg/g levels of organic compounds are areas of much current research

activity. We have collected the necessary materials and equipment required

to implement the procedure developed at Dow Chemical Research Laboratory for

the analysis of TCDD’s and TCDF's in soils. The procedure involves the

benzene extraction of soil, a three-^step column chromatographic clean-up,

further fractionation with both reversed^ and normal^phase HPLC , and analysis

using GC/MS.

The chemically modified chromatographi c packings have been prepared,

cleaned, and activated, and the appropriate collection zones for the chroma^

tographic steps have been determined.

We initially extracted both spiked soil samples and soil blanks. The

residues from the column chr omatographi c clean-up of these extracts have been

analyzed using GC/ECD techniques. We can quantitatively analyze these

particular soils for 2,3,7,8^TCDD at the 100 pg/g level with GC/ECD and no HPLC fractionation steps. 1 , 2, 3, 4-aTCDD can be used as an internal standard

and additional isomers are being evaluated as standards. Soil samples

containing potentially more interf erences have been obtained from sites

contaminated with oil containing dioxins and sites exposed to Agent Orange & other herbicide formulations. These samples are currently being analyzed.

82
GC/ECD techniques are being used to monitor method implementation and

modification and will be used to measure 2,3,7,8-TCDD in some of chromatographically suitable soil extracts. GC/MS will also be used for quantification of the 2,3,7,8-TCDD in the soil extracts. Accurate measurements by

either technique will require the acquisition of particular congeners to

demonstrate isomer specific determination of 2,3,7,8-TCDD in these fraction

techni ques

11. Development of a Laboratory Data Networking System (15320)

F. R. Guenther

In the past year, an IBM 9000 Computer/Integr ator was purchased. This

system is capable of collecting up to 4 channels of GC data at 30 Hz each,

plus simultaneous recalculation of stored chromatographic data. The processor , a Motorola 68000, has a greater capacity than required for the current

task and it was decided to use the system as the core of our laboratory

network

Software was written to integrate Varian 401 integrators, a HP 9825T

computer, a Tektronix 4010 graphics terminal, and a HP 7475 six pen plotter

into the network. With this system, we can transfer chromatograms from the

Varian 401 (or 402) to the IBM and use either commercial chromatography

software or our software to reprocess the data.

As with any multi-channel integrator, when more than one channel is in

use, several users will want to use the recalculation, display, or plotting

functions simultaneously. Thus a software program was written to allow these

functions at a graphics terminal, in effect producing a multi-user system.

This software allows up to 6 windows to be drawn on the terminal with

chromatograms or parts of chrcmatograms in any or all of the windows. Direct

chromatographic comparisons, point-to-point integrations, and retention time

determinations can be made. Reproduction quality plots can also be made of

chromatograms or of the window plots on the plotter. Formatted reports can also be sent to the HP 9825T for insertion into a data base or for farther

calculations. An additional alphanumeric terminal can also be connected to run other programs such as a Data Base Management Program or a Linear

Regression Program.

Our future plans are to move the multi-user functions to another

microcomputer and integrate an additional IBM 9000 into the network to allow

up to four external users to run application programs and access data on the

chromatographs and computers.

Additionally we are planning to interface the system to the N3S central

computer and will utilize the statistical and file handling utilities

available on that system to evaluate the chromatographic data.

83
1 2 . Research on Metal Chelate Columns (26111)

L. A. Alexander, N. Chessick, A. J. Fatiadi, S. A. Margolis, and D. J.

Reeder

The objective of this program is to develop solid phase supports which

bind metal ions. The metal*chelate supports can then be used to fractionate

proteins. The solid supports that we have investigated are styrene di vinyl*

benzene (SDVB) and Sepharose 6B (S6B) to which we have covalently bonded

imino*diacetate (IDA) groups. The metal ions are chelated by this functional

group

Between pH 4.5 and 7.2, the metal ions are tightly bound to these

supports and the materials exhibit colors characteristic of the bound metal.

These metal*chelate supports have been tested for their ability to bind serum

proteins and metal*reauiring enzymes. We have examined the effects of

protein concentration, solvent pH, solvent ionic strength, and solvent metal

ion concentration on the affinity of the proteins for the metal chelate

support materials.

Cu++

f Zn++

, Mn++

, Fe+++

, Fe++

, Co++

, and Ni ++ were tested individually.

At a pH of 5.5, 50$ or less of a serum sample was bound to the metal ion*IDA*

SDVB support when it was packed in a column. The amount of protein eluted

with each solvent varied with the ion species. Columns with the first three

metal ion species retained 22* 30* of the total protein under the eluting

conditions whereas the last four metal ion species retained less than 10$ of

the serum proteins. Examination of the ability of the metal*free IDA*SDVB

resin to bind serum proteins indicated that the protein fractionation was not

significantly different from that obtained with the Cu++ chelated support. As

the protein load on the metal*IDA*SDVB columns was increased, the amount of

protein in the third fraction (eluted with the solvent of highest ionic

strength) continued to increase while the amount of protein in the second

fraction decreased, indicating that the saturation level of the binding sites

of the column was being approached. The protein fractions obtained from each

column were analyzed by isoelectric focusing on thin layer polyacrylamide

gels. Examination of the protein species eluted in each fraction suggested

that the composition of the proteins for a given solvent condition was similar for each column and that the unretained fractions contained 8^

globulins; the second solvent eluted the Y*globulins; and the third solvent

contained the a*globulins.

Cu+ +

, Ni ++ and Zn ++ were chelated to separate samples of S6B. These

materials were packed in columns and their ability to bind serum proteins was tested. The metal ions fell into two categories: Cu ++

, which 3trongly bound

the proteins at pH 4.65, and Ni ++ and Zn ++ which bound only 40$ of the serum

proteins at pH 4.65. At pH 7.25, all three columns bound more than 90$ of

the applied protein. Some of the protein was eluted by increasing the ionic

strength of the solvents and the remaining proteins were eluted with increas*

ing concentrations of the metal ion (range 0.01 to 5$). As the pH decreased,

the proteins were eluted with solvents of lower ionic strength. There

appeared to be no saturation at the protein concentrations at which this was observed with the SDVB columns. Alkaline phosphatase (a Zn ++ requiring

enzyme) did not appear to be retained by the Zn ++ column at the "three pH's

tested. Similar results were obtained for urease (a Ni ++ requiring enzyme) on a N

++ col umn
The results obtained in these experiments indicate that the metal ions

modify the affinity of these supports for serum proteins. The degree of

modification appears to be minimal for the SDVB support. In the case of the

S6B support, the modification is more significant. The inability of these

columns to bind specific metaP*requiring enzymes, combined with the ability

of increasing concentrations of the metal ions to elute the bound serum

proteins, suggests that the fundamental mechanism of separation may be ion

exchange

13 . Influence of Physical and Chemical Parameters of Silica Substrates on

the Reversed^Phase Liquid Chromatographic Performance of Alkyl Bonded

Phases (15320)

L. C. Sander and S. A. Wise

Reversed-* phase chromatography on chemically bonded octadecylsilane

(C 18 ) stationary phases is by far the most popular separation mode currently

in use in liquid chr omatography . Understandably, the study of these phases

is an area of considerable interest, both from theoretical and from practical

points of view. Much of this interest is a result of differences in reten-*

tion and selectivity that exist among columns of the same phase type. In

earlier work, differences between monomeric, oligomeric, and polymeric C-jg

phases were examined for narrow and wide pore substrates. In our current

research, changes in chromatographic performance were examined as a function

of physical and chemical properties of the silica substrate. An understand^

ing of these effects may be valuable in explaining differences among comment

cial columns, and ultimately, in tailoring bonded phases for a specific

separation problem.

A total of 22 different silica substrates, with nominal pore sizes

ranging from 50-M000 A (5^100 nm) , were used in the preparation of the bonded

phases investigated in this study. Surface areas of these substrates,

measured by nitrogen adsorption, ranged from 32-^^433 m 2 /g. Polymeric phases

were synthesized on each of these substrates under controlled conditions.

The resulting surface coverage values increased with increasing substrate

pore size. Polycyclic aromatic hydrocarbons (PAH) were used to evaluate the

chromatographic properties of the phases. In general, phases prepared on

wide pore substrates were more selective toward PAH, and better separations

of PAH were obtained than with narrow pore substrates. These differences are attributed to a size exclusion mechanism during the bonded phase synthesis

that limits polymeric phase coverage with narrow pore substrates.

Substrate effects were further studied by synthesizing monomeric and

polymeric phases on silica pretreated with hydrochloric acid or sodium

hydroxide. No significant differences were observed in the chromatograph: ; properties of monomeric C-jq phases prepared on acid washed, base washed, r

untreated silica. However, with polymeric phase modification, differences ir. phase loading and column selectivity were noted, with the greatest polymeric

character occurring for the acid treated silica.

Although phase reproducibility is readily controlled for a giver. 3 ... substrate, the results of this study demonstrate clearly that larg° variations in phase loading and column performance may result when syr. th-srr

performed on different substrates. Pore size and acid/base pretreat:-.* -nr *.-

85
two parameters that have been observed to affect bonded phase syntheses;

other substrate parameters such as trace metal composition, not considered in

this study, may further influence phase characteri sties and work in this area continues

14. Optimization of Secondary Chemical Equilibria in Liquid Chromatograohy

(27201 )

‘ a

J. P. Foley and W. E. May

Conventional modern liquid chromatography (LC) uses "primary" chemical

equilibria, i.e., bulk mobile pnase^solute interactions and solute^stationary

phase interactions, to separate the analytes of interest. Other secondary

chemical equilibria (SCE) involving the analytes and the mobile or stationary

phase, i.e., acid-^base dissociation, complex formation, etc., are usually

deemed undesirable and are suppressed so that each analyte is eluted in one chemical form.

When analytes cannot be readily separated via conventional LC, SCE can and should be employed, if possible. With SCE-LC, the mobile phase is chosen

to provide an environment in which the analytes now exist in two or more

chromatographically distinct forms. Although seemingly paradoxical, it is

nevertheless true that separations exploiting the analytes’ SCE usually

succeed in instances where suppressing the SCE results in failure.

Although previous separations utilizing SCE-LC have been successful,

conditions for optimum resolution have been found mainly by triaP'and-^error

or by empirical optimization strategies. The purpose of the present study is

to examine SCE-LC from a fundamental point of view to develop an a priori

theory that predicts and explains the optimum isocratic mobile phase for the

separation of interest. The potential rewards are superior SCE-LC separa^

tions, in terms of reduced analysis times for separations currently being

performed, the ability to perform separations of previously unresolved

compounds in complex mixtures, and additional knowledge about retention

mechanisms in SCE-LC systems.

Because column efficiencies have frequently been lower when aqueous

SCE-LC has been employed, one goal was to increase the efficiency of aqueous

SCE-LC systems to levels which equaled that of conventional re versed-* phase

liquid chromatography (RPLC). We hypothesized that small amounts of the

appropriate organic solvent, when added to the aqueous mobile phase, will

"wet" the nonpolar stationary phase, thus improving the mass transf er sufficiently to achieve this goal. Methanol, ethanol, n-* propanol, and

acetonitrile were selected to test this hypothesis.

Our results show that n^propanol was by far the most effective organic

solvent, with 3^6? (by volume) improving chromato graphic efficiences by

factors of 10-*15, which approaches efficiencies observed in conventional

RPLC. Only slight improvements were observed with the other solvents.

More fundamental than the efficiency improvements we achieved is the

optimization of the selectivity (relative retention) in SCE-LC. Improvements

in selectivity can provide dramatic increases in resolution and/or large

reductions in analysis times.

86
Our theoretical investigation of selectivity-optimized SCE-LC is based

on a well established retention model in which the overall retention of an analyte is given by the weighted average of the retentions of its various

forms. Our results are summarized below:

1. Simple equations which predict the optimum mobile phase conditions have

been derived for all SCE-LC systems in which each of a pair of analytes

is limited to two forms (dimorphic).

2. Although it was not feasible to derive explicit equations for the

polymorphic (3 or more forms) cases due to the algebraic complexity of

the expressions, it was possible to predict, via simulation, the number

and locations of the mobile phase optima.

3. In most instances, the selectivity we predicted was significantly

higher than previous selectivity predictions, suggesting that the power

of SCE-LC has been substantially underestimated.

Our experiments to date have focused on acid-base equilibria in

r ever sed- phase systems at low to moderate ionic strengths (£ 0.03). Benzoic

acid and some simple derivatives have been used most extensively as test

solutes. Our results may be summarized as follows:

1. The retention model on which our SCE-LC theory and simulations are based was experimentally verified for the acid-base systems we examined. Thus our theory is valid for these systems.

2. The self-selecti vities [relative retentions of the two forms of the

analyte, i.e., k(form 1)/k(form 2)] of the ortho-substituted benzoic

acid isomers were found to be significantly higher than for the corresponding met a- and par a-* isomers. This may be due to intramolecular

H-bonding effects and will be investigated further.

3. The self-selecti viti es of the substituted benzoic acids varied considerably from one column to another. Therefore seme columns will be

better for a given SCE-LC application than others.

All the results discussed in this report apply to isocratic chromatographic systems. Seme additional experimental verification of the theory

for dimorphic analytes is needed, as well as a more thorough analysis for

polymorphic systems, before this part of the study is concluded. Following

this, we plan to pursue the optimization of selectivity in gradient SCE-LC

systems

1 5. Quantitative Analysis of Complex Mixtures by LC/MS/MS

R. G. Christensen and E. White V

Quantitative trace analysis for organic compounds in complex matrices

often requires time-consuming and laborious sample preparation. These

manipulations, in addition to lengthening the analysis time, can lead t' t- introduction of systematic errors. The combination of a liquid chromatogr • ' with a mass spectrometer (LC/MS) has been used in this laboratory to perf - -

87
such analyses without sample pretreatment. In some analyses, however,

interferences arise which cannot be resolved by either the liquid chromatographic separation or by the selectivity of the mass spectrometer.

The technique of tandem mass spectrometry (MS/MS) with collisioninduced dissociation offers an additional degree of selectivity. This is

accomplished by separating all the ions of a mass corresponding to the mass

of the ion species of interest and subjecting these ions to collision with

gas molecules. A second mass analyzer is then used to scan for fragment ions

specific to the ion of interest.

We have used this method to quantify dibenzothiophene in two oil

matrices, i.e., SRM 1582 (a petroleum crude oil) and SRC-II (a solventrefined coal liquid). A conventional liquid chromatograph was used in the

normal-phase mode, coupled to a triple auadrupole mass spectrometer by a preconcentrating interface of our own design. Since dibenzothiophene was found to lose sulfur on collision with nitrogen molecules, the first filtering quadrupole was set to mass m/z 18^4 (corresponding to M

+ for dibenzothiophene) and the second for m/z 152 (corresponding to neutral loss of

sulfur). The peak heights in ion current vs. time for oil samples were compared to those from the injection of external standards. Results agreed

with determinations by other, more laborious methods. For example, the

dibenzothiophene content of a solvent-refined coal liquid was found to be

1017 ± 78 yg/mL, compared to 1020 ± 70 yg/mL by GC/MS.

Using this method, the time required for each chromatographic run was only 7 minutes and the detection limit for dibenzothiophene was less than 20

ng. Thus the combination of LC/MS/MS provides a rapid and fairly sensitive

means of determining dibenzothiophene in oil matrices with no sample

pretreatment except an appropriate dilution.

1 6 . Thermal Crosslinking Procedure for Preparing Solvent-Stable FolymerFilm Electrodes (26101)

E. A. Blubaugh

Our immediate interest in chemically modified electrodes is in the

utilization of these electrocatalytic surfaces as selective and sensitive

analytical electrochemical detectors (LCEC) for liquid chromatography.

Published literature procedures for polymer film electrodes gave

results which were unsatisfactory. The major problems resulted from instability found for the film/electrode interfaces or dissolution of the film.

We have developed a thermal crosslinking procedure that yields a solvent

stable film and, in addition, a stable film/electrode interface.

The polymer was cast onto a 5 mm diameter superficially oxidized

platinum disc electrode surface from a 1 percent (W/W) methanol solution of

polyvinylpyridine/styrene copolymer (9:1), with benzoyl peroxide and triallyltrimellitate (e.g., 555, 1 055 , or 2055 crosslinking agent). An aliquot of

the solution was pipetted onto the prepared electrode. Evaporating the

methanol leaves a polymeric gel on the surface of the electrode. This

polymeric gel was heated, transforming the gel into a transparent film. These

polymer film electrodes were heat cured at 95 °C for 2.5 hours.

88
The polymer film electrodes prepared in this manner show an enhanced

stability toward a variety of solvents (polar or nonpolar) relative to the

conventional U-vinylpyridine/styrene copolymer. This stability is a result

of the thermosetting and crosslinking of the polymer film on the electrode

surf ace

These polymer film electrodes can be used to immobilize a variety of

catalyst molecules and use of these electrodes for the catalytic reduction of

organohalides will be discussed elsewhere. Further studies will be directed

towards the characterization of polymer film electrodes containing the

different catalyst molecules.

1 7 . Electrocatalytic Reduction of Ethylene Dibromide via Rhodium(II)

Tetraphenylporphyrin Dimer Derivatized Polymer Film Electrodes (26101)

E. A. Blubaugh

A variety of organometallic/transition metal complexes have been

immobilized within the solvent stable polyvinyl pyridine/styrene copolymer

(PVP/styrene) modified film electrodes. We will focus on the chemical

immobilization of rhodium(II) tetraphenylporphyrin [Rh(III)TPP] dimer

complexes, with their concomitant ability to reduce organohalides

catalytically

The preoaration of rhodium(II) tetraphenylporphyrin is easily

accomplished by the reduction of rhodium(III) tetraphenylporphyrin chloride,

via sodium borohydride and subsequent removal of the benzene solvent. These

dimer complexes can be immobilized in the previously prepared PVP/styrene

film electrodes by immersion of the electrodes in a benzene solution of the

dimer

There is no observed electroactivity for these dimer derivatized

electrodes in the potential window of ± 2 volts versus the saturated sodium

calomel reference electrode (S.S.C.E). However, when an aliquot of ethylene

dibromide is added (making the solution - 10"^ M in EDB), there are two

reduction processes observed at -1.325 volts and -1.677 volts versus S.S.C.E.

These peak potentials agree with the reduction potentials for rhodium(III)

tetraphenylporphyrin Br and rhodium(III) tetraphenylprophyrin CH 2 -CH 2 -Br (via

separate solution electrochemical studies). We propose the following

reaction scheme to describe the chemical process occurring in the film:

[Rh(II)TPP] 2

+ BrCH2 CH 2 -Br -> Rh(III)TPPBr + Rh(III)TPP(CH 2 -CH 2 -Br)

Rh(III)TPPBr + Rh( III )TPP-CH2 -CH 2 -Br [Rh(II)TPP] 2

+ Products

The catalytic mechanism is completed by the electrode reducing the

rhodium(III) species to rhodium(II) followed by dimer reformation.

These results are exciting for two reasons. The first is that alkyl

bromo species are not reduced until potentials more negative than -2.0C volt: vs S.S.C.E are reached (at unmodified electrodes). Our modified electr i-

catalytically reduce the bromo alkyl species at -1.677 volts or less. T.\

second reason is that these modified electrodes do not respond to aryl tr - species, such as bromobenzene , giving a selectivity between alkyl an! aryl

89
brcmo organic compounds. Future work will be directed towards further

characterization of the rhodium-* dimer complex to determine the properties of

the individual species involved in the catalytic reactions within the film.

1 8 . Refinement of the Mathematical Model for Charge Transport in PolymerFilm Electrodes (261 Oil

E. A. Blubaugh, R. A. Durst, and W. T. Yap

In an attempt to explain observed deviations from diffusion-controlled

behavior, we had previously developed a model for charge transport through

polymer films on chemically modified electrodes by considering both diffusion

of the electroactive group due to the concentration gradient in the polymer

film and the migration of charged groups caused by a constant electric field

across the film [1]. The current^time relationship for chronoamperometry was derived analytically for this very simple first model. The characteri stic

i*t 1/2 versus O^2 plots obtained for migration-*enhanced charge diffusion

closely described several . known systems of polymer-* mod if ied electrodes where

Cottrell (ideal diffusional) behavior is not followed. In addition, our model predicts behavior where the charge transport by migration opposes that

of diffusion and results in an initial decrease in the i»t

'

| /2 vs . t*\/2 plots

for chronoamperometric experiments. Polymer-*f ilm systems which exhibit this

type of behavior will be investigated to confirm our electromigration model.

We are also modifying the char ge*- transport model to predict the effects of

changes in the experimental parameters.

In the latest refinement of the migration model, we are investigating

the effect of allowing the electric field to decrease with time until it

reaches a zero field gradient at steady state instead of the constant

electric field across the polymer film as previously assumed. Since this

modification makes the model too complicated to solve analytically, we are using numerical simulations to obtain the current-*time relationships. As

expected, the overall shapes of the current-*time plots change little. Only

the magnitude of the current deviations from Cottrell behavior is progres*

sively reduced as a result of the decrease in the electric field gradient

with time.

The non^faradaic process of charging the polymer film, which acts as a capacitance, will also produce an enhancement to the observed current.

Therefore, we are also modeling by numerical simulation the effects of film

capacitance and resistance on the current-*time plots. Preliminary results

show that charging currents due to capacitance and resistance effects (i.e.,

RC time constant of the film) also produce i»t^2 V s. O^2 plots which have

positive initial slopes (in contrast to the zero slope for Cottrell behavior)

as in the case of migration enhancement. However, the finer features of

these plots are quite different in the two cases, and we are studying these

in more detail, both experimentally and theoretically.

[1] W. T. Yap, R. A. Durst, E. A. Blubaugh, and D. D. Blubaugh, J. Electro

Anal. Chem. 14J4, 69~75 ( 1983)*

90
19 . Electrochemical Characterization of a Series of Metal-Dithiosquarate

Complexes (27202)

G. S. Marbury

There has been considerable interest in dithiolene ligands with

strongly electron-withdrawing properties since these tend to stabilize lower,

sometimes uncommon, oxidation states of the central metal ion. Generally all

dithiolene complexes exhibit multiple states related by reversible oneelectron transfer reactions, the ease of which can be related to the

electron-withdrawing ability of the ligand (and attached substituent groups).

Maieonitrile dithiolate had been the most strongly electron-withdrawing of

the dithiolene ligands. Recently, however, oxocarbon derivatives have been

synthesized which exhibit greater electron-withdrawing character.

Preliminary studies with nickel showed that the order for ease of

reduction with the newer dithiolene ligands to be: dicyanom ethyl ene- dithiocroconate , di thiccroconate , and dithiosquarate . Of these ligands, the

dithiosquarate was chosen for detailed study because of its steric con- straints. Complexes of this ligand with five different transition metals

(Cu, Ni, Pt, Pd, and Au) were characterized electrochemi cally in dimethylformamide. Cyclic voltammetric studies show the redox couples in the

complexes to be quasi-reversible in nature. The diffusion coefficients

calculated from chronocouiometric data follow the expected trend of

increasing with the size of tne complex.

Because of the absence of useable spectral characteri sties , E0 ' and n values could not be determined spectroelectrochemi cally . Since thin-layer

pulse-coulometry is an alternative technique for determining the E 0 ' and n values for complexes with low extinction coefficients, we plan to include

this technique in the study of all the dithiosquarate complexes.

20. Preparation and Characterization of Reference Materials for EPA’s Water

and Hazardous Waste Programs (15320)

J. M. Brown-Thcmas , G. D. Byrd, S. N. Chesler, R. B. Christensen, F. R.

Guenther, L.R. Hilpert, W. F. Kline, W. A. MacCrehan, W. E. May, M. M.

Miller, R. E. Rebbert, D. J. Reeder, and L. T. Sniegoski

During" the past several years, we have supported the Quality Assurance

Programs of the Environmental Protection Agency. Work during the past year

has focused on the preparation of Reference Materials in the following areas:

1. Preparation of a Quality Assurance Solid Sludge Material for Hazardous

Waste Measurements

We have prepared and analyzed a quality assurance solid sludge material

for the Environmental Protection Agency in conjunction with the Inorganic

Analytical Research Division. Our objective was to identify and quantify

several organic compounds, most of which are priority pollutants, in an actual composite solid sludge and in aqueous leachates of that mater, al. 7n

experimental plan for sampling and analysis was designed using accept-:

statistical procedures to enable us to analyze the components of van a:.'..*,

contributed by the sample itself, the work-up procedure, and tne 0

' ' measurement step. Aqueous leachates of the composite sludge were pr* :

91
and analyzed according to standard EPA procedures. The concentrations of

analytes in the aqueous leachates were in the 1-MOO part-*per^billion range.

The results of the study showed that the variabilities of the work-up

procedure and GC/MS measurements were major contributors to the overall

uncertainty in the determined values. Approximately 100 units of the solid

sludge material were delivered to the EPA Environmental Monitoring and

Support Laboratory, Las Vegas, NV.

2. Preparation of a Synthetic Urine Reference Material Containing Phenolic

Compounds and Plasticizers

A synthetic urine reference material was prepared by fortifying a base

material containing electrolytes, nitrogenous substances, and other compo-*

nents normally found in urine with 2, 4,5-*trichlorophenol , pentachlorophenol

,

phenol, p^nitrophenol , bis(2-*ethylhexyl)phthalate and bi s( 2-* ethyl he xyl )-* adipate at a range of concentrations between 0.1 and 5 ppm. The gravimetric

concentrations of the phenols were verified and stability measurements

conducted using liquid chromatography. The initial concentrations of the

esters were approximately 0.1 ppm and decreased with time due to adsorptive

losses on the container walls. One hundred & fifty units of the reference

material and 400 units of the base stock were delivered to the EPA

Environmental Monitoring and Support Laboratory in Las Vegas, NV.

3. Preparation of a Human Serum Reference Material Containing

Polychlorinated 3iphenyls

A set of human serum samples containing known amounts of poly*

chlorinated biphenyls (PCB's) have been prepared for use as reference

materials. The human serum, which was obtained commercially, was stripped of

low molecular weight contaminants by charcoal filtration. The PC3's were

added gravimetri cally as a commercial mixture, Aroclor 1260 (60$ chlorine by

weight), at two concentration levels: 10 ng/g and 50 ng/g. These levels

represent the high-normal and toxic levels of PCB's found in the human population. Measurements of the PCB concentrations were made by gas chromato-*

graphy to confirm the gravimetric values. The measured values were 11.2 ± 0.4 ng/g and 60.0 ± 1.3 ng/g. Three hundred samples at each concentration

level, as well as a serum blank, were prepared and will be delivered to the

EPA EMSL laboratory in Las Vegas, NV.

4. Analysis of EPA Calibration and Performance Evaluation Samples.

This work was undertaken as part of the Center for Analytical

Chemistry's effort to assist EPA's Quality Assurance Branch in Cincinnati by

providing NBS traceability on their calibration solution standards and on

quality assurance samples prepared by outside contractors. The following

samples were analyzed by gas chromatography with electron capture or flame

ionization detection: ''Volatile Organics" (nine halocarbons in methanol);

"Trihalomethanes" (chloroform, bromoform, bromodi chloromethane and dibrcmo^

chlor omethane in methanol); "Chlorinated Hydrocarbon Pesticides" (lindane,

endrin, methoxychlor in acetone). "Temik" samples (aldicarb, aldicarb

sulfone, and aldicarb sulfoxide in acetonitrile) were analyzed by liquid

chromatography with both UV detection and fluorescence detection after post

column derivitization . "Trace Metals" (26 trace metals in water) were analyzed in the Inorganic Analytical Research Division by inductively coupled

plasma spectrometry and one of several other techniques which included Atomic

92
Absorption Spectroscopy, Flame Emission Spectroscopy, Laser Enhanced Ionization Spectroscopy , Direct Current Plasma Emission Spectroscopy, and Neutron

Activation Analysis.

At this point, NBS Reports of Analysis are used as the means for

establishing traceability. The Center is currently in the process of

drafting a document that provides a definition of " traceability"

21. Certification of a Priority Pollutant Phenols in Methanol SRM (15602)

J. M. Brcwn-Thomas , S. N. Chesler, D. K. Hancock, W. F. Kline, W. E. May, R. M. Parris, and R. E. Rebbert

Certification of SRM 15 3-4, Priority Pollutant Phenols in Methanol, has

been completed. The SRM was prepared in-house and contains the eleven

phenols included on the EPA's List of Priority Pollutants. The SRM is

intended primarily for use in calibrating chromatogr aphi c instrumentation

used in the determination of phenols and, because of its miscibility with

water, can also ce used to fortify aqueous samples with known concentrations

of phenols. The individual phenolic compounds in the SRM are: 2-nitrophenol

2, 4-di chlorophenol ; 2, 4, 6-tri chlorophenol ; 4-ni trophenol ; pentachlorophenol

4-chloro-m-cresol ; 4, 6-dinitro-o-cresol ; 2, 4-dini trophenol; o-chlorophenol

and 2,4 dimethyiphenol

Randomly selected samples were analyzed for four of the eleven phenols

by HPLC on a reversed-phase C-8 (5 pm) column using an aqueous acetic

acid/acetonitrile/methanol mobile phase and UV detection at 254 nm. Four

external standard solutions were used to provide response factors for HPLC

quantification. Seven of the eleven compounds were determined by gas

chromatographic (GC) analysis on a fused silica 0V-1701 capillary column with

flame ionization detection. Four independent GC calibration solutions were

used to obtain responses relative to 6-chloro-m-cr esol , the internal standard. The gravimetric concentrations were calculated from the mass of each

phenolic compound added to a known mass of methanol in the preparation of the

SRM.

The certified values for the concentrations of ten of the phenols were

determined from the concordant results of two independent analytical techniques. The information value provided for 2, 4-dini trophenol is based only

on the results from HPLC analyses, but with UV detection at both 254 and 290

nm. The SRM is available through the Office of Standard Reference Materials.

22. Certification of a Diesel Particulate SRM (15320)

H. X. Gu, L. R. Hilpert, W. F. Kline, W. A. MacCrehan, and W. E. May

It is generally thought that the increasing use of diesel engines p:ses

a potential human health risk. Organic solvent extracts of diesel exhaust

particulates exhibit direct acting mutagenicity in the Ames test [1-3). In

addition, diesel engines produce 50-80 times more particles than catalyst

equipped spark ignition engines, with the diameters of the agglomerated

particles being typically less than 1 ym. Particles in this size range an-- thought to be extremely harmful to humans because they may be respire v; : deposited in the lungs [4]. Because of these reasons, there has been a gr»- .• deal of interest in the analytical characterization of organic component

93
great deal of interest in the analytical characterization of organic compo^

nents on diesel exhaust particulate matter. The Department of Defense,

Department of Energy, Environmental Protection Agency, and Coordinating

Research Council are all funding contract research in this area.

The major organic components in diesel exhaust particulates appear to

be the polynuclear aromatic hydrocarbons (PAH). The PAH have been found to

exhibit less than 5 percent of the direct-*act ing mutagenicity associated with

organic extracts of diesel particulate matter [2].

Diesel particulate extracts have also been found to contain several PAH

derivatives, including hydroxy, dihydroxy, keto , quinone, car boxaldehyde

,

acid anhydride, and nitro substituents. Of these, the nitro-PAH are thought

to be the most active.

During the past year we have measured the concentrations of a number of

PAH and nitrated PAH on a diesel exhaust particulate sample donated by the

Coordinating Research Council Inc., Atlanta, GA. by at least two methods

each. The PAH were determined by LC-* fluorescence and GC/MS after soxhlet

extraction with methylene chloride and methanol/toluene respectively. The

nitrated PAH were determined by soxhlet extraction and either LC-* fluorescence

after on-line reduction to the corresponding amine, soxhlet extraction

followed by GC/MS, or ultrasonic extraction and LC with reductive electro-*

chemical detection.

The SRM is being packaged as units consisting of three 100 mg ampoules

and should be available in late fall after statistical analysis of the data

has been completed.

[1] Ames, B. N. ; McCann, J; and Yamasaki, E; Mutat. Res. 3J_, 3^7^36^

(1975).

[2] Pepelko, W. E. ; Donner , R. M.; Clarke, N. A., Eds. ’’Health Effects of

Diesel Engine Emissions: Proceedings of an International Symposium,

Dec 3^5, 1979; U.S. Environmental Agency: Cincinnati, OH, 1980;

EPA^600/9^80-057.

[3] Huisingh, J. ; Bradow, R. ; Jungers, R. ; Claxton, L. ; Zwiedinger, R.;

Tejada, S. ; Bumgarner, J.; Duffield, F. ; Waters, M. ; Simmon, V. F.

Hare, C.; Rodriguez, C.; Snow, L. M. ’’Application of Short Term

Bioassays in the Fractionation and Analysis of Complex Environmental

Mixtures"; Waters, M. D.; Nesnow, S. ; Huisingh, J. ; Sandu, S. ; Claxton,

L., Eds.; Plenum Press: New York, 1978; EPA -*600/9^78^027.

[M] Chan, T. L. ; Lee, P. S. ; Hering, W. E. JAT, J. Appl. Toxicol . 1981, 1,

77^82.
23. Certification of a Gas Chromatography/Mass Spectrometry Performance SRM

( 26108 )

J. M. Brown-^Thomas , 3. N. Chesler, R. G. Christensen, L. R. Hilpert, R. C. Pauls (500), R. E. Rebfcert, L. T. Sniegoski, and E. White V.

This SRM is the first of a possible series intended to provide

materials suitable for testing the performance of analytical instruments.

Gas chromatography/ mass spectrometry (GC/MS) was selected as a suitable test

case. Since there are only a few U.S. manufacturers of GC/MS instruments,

most use the same test compounds. However, both manuf acturers and end users must prepare their own test materials.

SRM 1543 provides materials with certified concentrations of two

compounds most commonly used to test the sensitivity of gas

chromatography/ mass spectrometer systems. It will provide instrument

manufacturers and their customers with an independent source of test samples

for evaluating instrument performance.

Certification was based on the gravimetric values from the preparation

of the SRM as well as analytical values determined by gas chromatography. The

SRM, as issued, consists of 1 mL of each of four hexane solutions. The

material and certified values are; methyl stearate at 0.99 ± .02 ng/uL,

methyl stearate at 4.98 ± .03 ng/uL, benzophenone at 1.01 ± .02 ng/yL, and

benzophenone at 5.01 ± .07 ng/yL. The certified values are valid between 13

°C and 28 °C

95
C. Outputs and Interactions

(Organic Analytical Research Division)

1 . Publications

Bunding, K. A., Durst, R. A., and Bell, M. I., Surf ace-Enhanced Raman

Spectroscopy of N-Methylpyri dinium Cation and Pyridine: Identification

of Surface Species, J. Electroanal. Chem. 1 50 , M37-446 (1983).

Conzemius, R. J., Simons, D. S., Shankai, Z. , and Byrd, G. D., Laser Mass

Spectrometry of Solids: A Bibliography 1963-1982, Microbeam

Analysis—1 983, R. Gooley, ed., San Francisco Press, San Francisco, CA,

301-322 (1983)

Coxon, B. , Two-Dimensional J-Resolved Proton Nuclear Magnetic Resonance

Spectroscopy of Hydroxyl Proton Coupled a- and S-D-Glucose, Anal. Chem.

55, 2361 (1983).

Elder, R. C., Blubaugh, E. A., Heineman, W. R., Burke, P. J., and McMillin,

D. R., Thin-Layer Spectroelectrochemical Studies of Copper and Nickel

Unsymmetri cal Schiff Base Complexes, Inorg. Chem. 2£, 2777 (1983).

Fultz, M. L. and Durst, R. A., Investigation of Two Multichannel Image

Detectors for Use in Spectroelectrochemistry , Talanta 3£» 933-939

(1 983).

Guenther, F. R. and Chesler, S. N. , A Post-Column Solvent Trapping Technique

for the Analysis of Very Volatile Halocarbons, J. High Res. Chrom. and

Chrom. Comm. 6_, 1 6 ( 1 983).

May, W. E. , Brown-Thomas , J. M., Chesler, S. N. , Guenther, F. R. , Hilpert,

L. R., Parris, R. M., Richie, K. L., Sonnefeld, W. J. , Wise, S. A., and

Hertz, H. S. , Interlaboratory Comparisons of Quantitative Analyses of

Individual Compounds in Simple and Complex Mixtures, in Advanced

Techniques in Synthetic Fuels Analysis , C. W. Wright, W. C. Weiner, and

W. D. Felix, eds., Technical Information Center, U.S. Department of

Energy, 381 -^404 ( 1983) .

Mayfield, H. T. and Bertsch, W., An Algorithm for Rapidly Organizing Gas

Chr omatographi c Data into Data Sets for Chemometric Analysis, J. Computer Applications in the Lab. 1_, 1 30-1 36 ( 1983).

Peters, P. N., Hester, H. B., Bertsch, W. , Mayfield, H. T. , and Zatko, P.,

IV. Air Sampler (STS-2, ~3» -M) Induced Environment Contamination

Monitor ( IECM) Summary Report (NASA TM-8252 10, E. R. Miller, ed.,

Marshall Space Flight Center, AL, 8-10 (1983).

Sander, L. C., Callis, J. B. , and Field, L. R., Fourier Transform Infrared

Spectrometri c Determination of Alkyl Chain Conformation on Chemically

Bonded Reversed-Phase Liquid Chromatography Packings, Anal. Chem. 55,

1068-1075 (1983).

Sonnefeld, W. J. , Zoller, W. H. , and May, W. E. , A Dynamic Coupled- Column

Liquid Chromatographic Method for Determination of Vapor Pressures of

Organic Compounds, Anal. Chem. 55, 275-280 (1983).

96
Velapoldi, R. A., White, F. A., May, W. E. , and Eberhardt , K., Speetrof luorometric Determination of Polycyclic Aromatic Hydrocarbons in Aqueous

Effluents fran Generator Columns, Anal. Chem. 55, 1896-1901 ( 1983).

Wasik, S. ?., Miller, M. M., Tewari , Y. B. , May, W. E., Sonnefeld, W. J.,

DeVoe, H., and Zoller, W. H. , Determination of the Vapor Pressure,

Aqueous Solubility, and Octanol-Water Partition Coefficient of Hydrophobic Substances by Coupled Generator Column/Liquid Chrcmatographi

Methods, Res. Rev., Springer-Verlag, New York, NY, 85 (1983).

Wasix, S. P. , Tewari, Y., Miller, M. M., and Purnell, J. H. , Measurements of

the Octanol/Water Partition Coefficient by Chromatographic Methods, NBS

J. Res. 87, 31 1 ( 1983) .

Wise, S. A., Campbell, R. M., May, W. E. , Lee, M. L. , and Castle, R. N. , Normal- and Reversed-Phase Liquid Chromatographic Separations of Polycyclic Aromatic Sulfur Heterocycles, in Polynuclear Aromatic Hydrocar- bons; Formation, Metabolism, and Measurement , M. Cooke and A. J. Dennis, eels., 3attelle Press, Columbus, OH, 1247-1266 (1 983).

Wise, S. A., Sander , L. C., and May, W. E. , Modification of Selectivity in

Reversed-Phase Liquid Chromatography of Polycyclic Aromatic Hydrocarbons Using Mixed Phases, J. Liq. Chromatog. 6_, 2709-2721 ( 1983).

Engman, H. , Mayfield, H. T. , Mar, T. , and Bertsch, W. , Classification of

Bacteria by Pyrolysis/Capillary Column GC/MS and Pattern Recognition,

J. Anal. Appl . Pyrol. 6, 137-156 (1984).

Espinosa-Leniz, R., Analysis of Polypeptides by High Resolution Field

Desorption Mass Spectrometry, Thesis submitted to the American University, Washington, DC (1 984).

Foley, J. P. and Dorsey, J. G., A Review of the Exponentially Modified

Gaussian (EMG) : Evaluation and Subsequent Calculation of Universal

Data, J. Chromatog. Sci. 22, 40-46 (1984).

Jacobson, D. B. , Byrd, G. D., and Freiser, B. S. , Gas Phase Reactions of Co*

and Rh+ with Toluene, Cycloheptatriene, and Norbornadiene , Inorg. Chem.

23, 553-557 (1984).

Kamat , P. V., Fox, M. A., and Fatiadi, A. J. , Dye Loaded Polymer Electrodes.

Photoelectrochemical Sensitization by Croconate Violet in Polymer

Solutions and Films, J. Am. Chem. Soc. 1 06 , 1191-1197 (1984).

MacCrehan, W. A. and May, W. E., Oxygen Removal in Liquid Chr omatography

Using Zinc/Oxygen Scrubber Column, Anal. Chem. 56_, 625-628 ( 1984).

May, W. E. , Chesler, S. N., Hilpert, L. R., Hertz, H. S. , Rebbert, R. E. , Vogt, C. R., and Wise, S. A., Characteri zation of Polycyclic Aromatic

Hydrocarbons in Air Particulate Extracts by Liquid and Gas Chromatographic Methods, in Identification and Analysis of Organic Pollute^:

in Air, L. R. Keith, ed., Butterworth Publications. Woburn. MA. 197-2

TT9PT.

97
May, W. E. and Wise, S. A., Liquid Chromatographic Determination of

Polycyclic Aromatic Hydrocarbons in Air Particulate Extracts, Anal.

Chem. 56, 225-232 ( 1 984)

Miller, M. M., Ghodbane, S. , Wasik, S. P. , Tewari , Y. B. , and Martire, D. E. , Aqueous Solubilities, Octanol/Water Partition Coefficients, and

Entropies of Melting of Chlorinated Benzenes and Biphenyls, J. Chem.

Eng. Data 29, 1 84 (1984) .

Rebbert, R. E. , Chesler, S. N. , Guenther, F. R. , and Parris, R. M., Liquid

Chr omatography-Gas Chromatography Procedure to Determine the Concentration of Dibenzothiophene in a Crude Oil Matrix, J. Chromatog. 284,

211 (1984).

Roberts, G. D. and White V, E. , Silver Sulfonates as Mass Standards in Field

Desorption Mass Spectrometry , Biomed. Mass Spectrom. 5, 273-275

(1984).

Sander, L. C. and Wise, S. A., Synthesis and Characterization of Polymeric

Ci8 Stationary Phases for Liquid Chromatography , Anal. Chem. 56,

504-51 0 ( 1 984).

Welch, M. J., Cohen, A., Hertz, H. S. , Ruegg, F. C., Schaffer, R. , Sniegoski,

L. T. , and White V, E. , An Isotope Dilution Mass Spectrometric Method

for the Accurate Determination of Serum Urea, Anal. Chem. 56_, 713-719

(1 984).

Wise, S. A., Fitzpatrick, K. A., Harrison, S. H. , and Zeisler, R. , Operation

of the U.S. Pilot National Environmental Specimen Bank Program, in

Environ. Specimen Banking and Monitoring as Related to Banking , R. A. Lewis, N. Stein, and C. W. Lewis, eds., Martinus Nijhoff Publishers,

Boston, 108-126 ( 1984) .

Yap, W. T. , Blubaugh, E. A., Durst, R. A., and Burke, R. T. , Spectroelectrochemistry of a System with Product Deposition on the Electrode, J.

Electroanal. Chem. 1 60 , 73-78 (1984).

Zeisler, R., Harrison, S. H. , and Wise, S. A., Analysis of Human Liver

Specimens in the U.S. Pilot National Environmental Specimen Bank

Program, in Environ. Specimen Banking and Monitoring as Related to

Bank ing , R. A. Lewis, N Stein, and C. W. Lewis, eds., Martinus Nijhoff

Publishers, Boston, 331-351 (1984).

Zeisler, R., Harrison, S. H. , and Wise, S. A., Trace Elements in Human Livers

Using Quality Control in the Complete Analytical Process, Biol. Trace

Elem. Res. 6, 31-49 ( 1984) .

Blubaugh, E. A., Chiang, C. K., and Yap, W. T. , Electrochemical Behavior of

Doped Polyacetylene Films, J. Electroanal. Chem., in press.

Botto, R. E. and Coxon, B. , Two-Dimensional Proton J-Resolved NMR

Spectroscopy of Neomycin B, J. Carbohydr. Chem., in press.

98
Burke, R. T. , 31ubaugh, E. A., Yap, W. T. , and Durst, R. A., Electrochemical

Investigation of N-Methyl-*4-(5-phenyl-2-oxazolyl )pyridinium p-Toluenesulfonate, J. Electrcanal. Chem., in press.

Coxon, 3., Two-Dimensional Proton Chemical Shift Correlated NMR Spectroscopy

of Digitoxose, J. Carbohydr. Chem., in press.

Durst, R. A., Clinical Electrode Potenticmetry : Sources of Error, Reference

Methods and Materials, Direct Potentiometri c Measurements in 31ood,

W. Koch, ed., in press.

Fatiadi, A. J., New Applications of Tetracyanoethylene in Organic Chemistry,

Synthesis, in press.

Fatiadi, A. J., The Oxidation of Organic Compounds by Active Manganese

Dioxide, Oxidative Procedures in Org . Chem. Involving Metal Compounds,

W. J. Mijs, ed., Plenum Press, London, in press.

Fatiadi, A. J., Priority Toxic Pollutants in Human Urine: Their Occurrence

and Analysis, Environment International, in press.

Fletcher, R. A. and Fatiadi, A. J., Laser Ionization Mass Spectrometry of

Poly( L-Vinyl pyridine ) , Anal. Chem., in press.

Foley, J. P. and Dorsey, J. G., Clarification of the Limit of Detection in

Chromatography, Chromatograph! a , in press.

Hilpert, L. R., Byrd, G. D., and Vogt, C. R., Enhanced Selectivity for Benzo-

[a]pyrene and Other Polycyclic Aromatic Hydrocarbons Using Negative Ion

Chemical Ionization Mass Spectr ometry , Anal. Chem., in press.

MacCrehan, W. A. and May, W. E. , Determination of Nitro-Polynuclear Aromatic

Hydrocarbons in Diesel Soot by Liquid Chr omatography with Fluorescence

and Electrochemical Detection, in Proc. 8th Internatl. Sym. on Polynuclear Aromatic Hydrocarbons , Columbus, OH, October 1 983, in press.

Margolis, S. A. and Coxon, B. , Amino Acid Analysis of Angiotensin I by Proton

NMR Spectroscopy, Anal. Biochem., in press.

Mattammal, M. B. , White V, E. , Zenser, T. V., and Davis, B. B. , Mass

Spectrometry of 2-Substituted-Y-Arylthiazol es . III. Identification of

Microsomal Nitroreduction Products by Mass Spectrometry , Biomed. Mass

Spectrom., in press.

Sander, L. C. and Wise, S. A., The Influence of Substrate Parameters on Column Selectivity with Alkyl Bonded-Phase Sorbents, J. Chromatog., i r. press

Sander, L. C. and Wise, S. A., Synthesis and Characterization of C^q

Stationary Phases for the Liquid Chromatographic Separation of Polycyclic Aromatic Hydrocarbons , in Proc. 8th Internatl. Sym. or. Polynuclear Aromatic Hydrocarbons, Columbus, OH, October 1953,

press

99
Wasik, S. P. , Schwarz, F. P. , Tewari , Y. B. , Miller, M. M., and Purnell,

J. H., A Head-Space Method for Measuring Activity Coefficients,

Partition Coefficients, and Solubilities of Hydrocarbons in Aqueous

Solutions, NBS J. Res., in press.

Wise, S. A., Analytical Techniques for the Determination of Petroleum Hydrocarbons and Combustion Products, in Pollution and the Protection of

Water Quality , R. W. Risebrough, ed., Hemisphere Publishing, New York,

in press.

Wise, S. A., Interlaboratory Comparisons and the Use of Reference Materials

for Quality Control of Analytical Methodologies, in Pollution and the

Protection of Water Quality , R. W. Risebrough, ed., Hemisphere

Publishing, New York, in press.

Wise, S. A., Recent Progress in the Determination of Polycyclic Aromatic

Hydrocarbons by High-Performance Liquid Chromatography, in Handbook for

Polycyclic Aromatic Hydrocarbons; Volume II , A. Bjbrseth and

T. Ramdahl, eds., Marcel Dekker, New York, NY, in press.

Wise, S. A., Chesler, S. N. , Hilpert, L. R., May, W. E. , Rebbert, R. E. , and

Vogt, C. R. , Characterization of Polycyclic Aromatic Hydrocarbon

Mixtures from Air Particulate Samples Using Liquid Chromatography, Gas

Chromatography, and Mass Spectrometry , in Proc. 8th Internati. Sym. on Polynuclear Aromatic Hydrocarbons , Columbus, OH, October 1983, in

press

Wise, S. A. and Zeisler, R. , The Pilot Environmental Specimen Bank Program,

Environ. Sci. Technol., in press.

Zeisler, R. and Wise, S. A., Quality Assurance and Protocols in Sampling and

Sample Preparation of Biological Samples, in Proc. Internati. Sym.

Biol. Ref. Matls. for Nut. Anal., Philadelphia, PA, September 1983, in

press

2. Talks

S. A. Wise, "Standard Reference Materials for Trace Organic Analysis," Fourth

Ulmer Symposium on Analytical Chemistry, University of Ulm, Ulm,

Germany, October 6, 1983. Invited

R. A. Durst, "Novel Approaches to Organic Electroanalysis," Analytical/

Nuclear/Environmental Division Seminar, University of Maryland, College

Park, MD, October 21, 1983. Invited

J. M. Brown-Thomas , "Analysis of Organic Nutrients by High-Performance Liquid

Chromatography," Third NBS/ADABSE Analytical Chemistry Workshop, NBS,

Gai thersburg , MD, October 25, 1983.

L. C. Sander , "Theory and Practice of High-Performance Liquid

Chromatography," Third NBS/ADABSE Analytical Chemistry Workshop, NBS,

Gaithersburg, MD , October 25, 1983.

100
W. A. MacCrehan, "Determination of Nitro-Polynuclear Aromatic Hydrocarbons in

Diesel Soot by Liquid Chromatography with Fluorescence and Electrochemical Detection," Eighth International Symposium on Polynuclear

Aromatic Hydrocarbons, Battelle Laboratories, Columbus, OH, October 27,

1 983.

S. A. Wise, "Characterization of Polycyclic Aromatic Hydrocarbon Mixtures

from Air Particulate Samples Using Liquid Chromatography, Gas Chromatography, and Mass Spectrometry ," Eighth International Symposium on Polynuclear Aromatic Hydrocarbons, Columbus, OH, October 27, 1983.

E. A. Blubaugh, "Electrochemical Techniques: Cyclic Voltammetry and Hybrid

Electrochemical Techniques," Third NBS/ADABSE Analytical Chemistry

Workshop, NBS, Gaithersburg, MD , October 28, 1983.

S. N . Chesler, "Gas Chromatography," Third NBS/ADABSE Analytical Chemistry

Workshop, NBS, Gaithersburg, MD , October 28, 1983.

B. Coxon, "Two-Dimensional NMR Spectroscopy," Third NBS/ADABSE Analytical

Chemistry Workshop, NBS, Gaithersburg, MD , October 28, 1983. Invited

D. J. Reeder, "Two-Dimensional Electrophoresis," Third NBS/ADABSE Analytical

Chemistry Workshop, NBS, Gaithersbur g, MD , October 28, 1983.

S. A. Wise, "Synthesis and Characterization of C-jg Stationary Phases for the

Liquid Chromatographic Separation of Polycyclic Aromatic Hydrocarbons ,

Eighth International Symposium on Polynuclear Aromatic Hydrocarbons,

Columbus, OH, October 28, 1983.

L. R. Hilpert, "Selectivity of Detection for Benzo[a]pyrene and Other PAH

Using Negative Ion Chemical Ionization Mass Spectrometry," N3S/D0E

Analytical Characterization Group Meeting, Ames, IA, November 2, 1983*

Invited

W. E. May, "High-Performance Liquid Chromatographic Determination of

Nitrated-Polynuclear Aromatic Hydrocarbons in Complex Mixtures," 35th

Southeast Regional Meeting of the American Chemical Society, Charlotte,

NC, November 9, 1983. Invited

E. White V, "Isotope Dilution GC/MS Applied to Clinical Chemistry,"

Department of Chemistry, University of Maryland, College Park, MD

,

November 18, 1983. Invited

R. G. Christensen, "LC/MS with Continuous Preconcentration , " Analytical

Seminar, Chemistry Department, University of Nebraska-Lincoln , Lincoln,

NE, November 21, 1983. Invited

B. Coxon, "Two-Dimensional NMR Spectroscopy , " Towson State University,

Towson, MD , December 16, 1983. Invited

W. A. MacCrehan, "Adventures in LCEC," Washington Chromatography Discuss irr

Group, Rockville, MD , January 19, 198H. Invited

101
E. A. Blubaugh, "Spectroelectrochemistry of a System with Product

Deposition," Gordon Research Conference on Electrochemistry , Santa

Barbara, CA, January 24, 1984.

R. A. Durst, "Electrochemical/Spectroelectrochemical Investigation of

N-Methyl-4-(5-phenyl-2-oxazolyl )pyridinium p-Toluenesulfonate Laser

Dye," Gordon Research Conference on Electrochemistry, Santa Barbara,

CA, January 24, 1984.

R. A. Durst, "Electrochemical Approaches to Organic Analysis," McGill

University Chemical Society, Montreal, Canada, February 7, 1934.

Invited

D. K. Hancock, "Characterization of Proteins by Two-Dimensional Electrophoresis," Washington Chromatography Discussion Group, February 16,

1984. Invited

B. Coxon, "Two-Dimensional NMR Spectroscopy of Carbohydrates," Villanova

University, Villanova, PA, February 21, 1984. Invited

G. D. Byrd, "Analysis of a Solid Sludge Material by GC/MS," 35th Annual

Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy,

Atlantic City, NJ, March 5, 1984.

F. R. Guenther, "Use of Polynuclear Aromatic Hydrocarbon Generator Columns

for Calibrating Air Sampling Systems," 35th Annual Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, Atlantic City,

NJ, March 5, 1984.

L. R. Hilpert, "Selectivity for Benzo[a]pyrene and Other Polycyclic Aromatic

Hydrocarbons Using Negative Ion Chemical Ionization Mass Spectrometry ,

35th Annual Pittsburgh Conference on Analytical Chemistry and Applied

Spectroscopy, Atlantic City, NJ, March 6, 1984.

M. M. Miller, "GLC Separation Behavior of Polychlorinated Biphenyl Isomers

Between a Nematic Liquid Crystal Stationary Phase and a Nonpolar Hydrocarbon Phase (Apolane-87) ," 35th Annual Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy , Atlantic City, NJ,

March 6, 1984.

W. F. Kline, "The Use of Perdeuterated PAH as Internal Standards for the HPLC

Determination of PAH in Complex Mixtures," 35th Annual Pittsburgh

Conference on Analytical Chemistry and Applied Spectroscopy, Atlantic

City, NJ, March 8, 1984.

W. E. May, "Organic Analytical Research at the National Bureau of Standards,"

Department of Chemistry, Hampton Institute, Hampton, VA, March 16,

1984. Invited

A. J. Fatiadi , "Structure of Metal-Coordinated Polymers: The Chemistry of

Oxo-and Pseudo-Oxocar bons , " Catholic University, Washington, DC,

March 23, 1984. Invited

102
W. E. May, "Liquid Chromatographic Methods for the Determination of

Polycyclic Aromatic Hydrocarbons and Their Nitrated Derivatives in

Environmental Samples," Environmental Chemistry Division, Johns Hopkins

University, Baltimore, MD , April 6, 1984. Invited

G. S. Marbury, "Electrochemical Characterization of a Series of Copper

Dithioxocarbon Complexes," 187th National Meeting of the American

Chemical Society, St. Louis, MO, April 10, 1984.

S. A. Wise, "Characterization and Quantification of Polycyclic Aromatic

Hydrocarbons in Air Particulate Matter from Washington, DC and

Philadelphia, PA," Conference and Workshop on C-enotoxic Air Pollutants,

Rougemont , NC, April 25, 1984. Invited

S. A. Margolis, "Chromatography," Alice Deal Junior High School, Washington,

DC, May 4, 1984. Invited

E. A. Blubaugh, "Study of 5-Phenyl-2- (4-Pyridinium)0xazole Methyl Tosylate:

Spectroelectrochemistry of a Precipitating System," 1 65th Meeting of

the Electrochemical Society, Cincinnati, OH, May 7, 1984.

L. C. Sander, "The Influence of Substrate Parameters on Column Selectivity

with Alkyl Bonded Phase Sorbents," Eighth International Symposium on Column Liquid Chromatography, May 22, 1984.

J. M. Brown-Thomas , "Determination of Phenols in Complex Matrices by HighPerformance Liquid Chromatography/Electrochemistry , " 1 8th Middle

Atlantic Regional Meeting, Newark, NJ, May 23, 1984.

K. J. Ng, "A Candidate Definitive Method for the Determination of Serum

Creatinine by Isotope Dilution/Mass Spectrometry," 32nd Annual Confei

ence on Mass Spectrometry and Allied Topics, San Antonio, TX , May 28,

1984.

G. D. Byrd, "Analysis of a Solid Sludge Material by GC/MS," 32nd Annual

Conference on Mass Spectrometry and Allied Topics, San Antonio, TX

,

May 29, 1984.

L. R. Hilpert, "Measurement of Toxic Organic Compounds in Environmental

Samples Using Negative Ion Chemical Ionization Mass Spectrometry," 32nd

Annual Conference on Mass Spectrometry and Allied Topics, San Antor.io,

TX, May 29, 1984.

M. J. Welch, "Photodissociation of Ions Generated by Soft Ionization

Techniques," 32nd Annual Conference on Mass Spectrometry and Allied

Topics, San Antonio, TX, June 1, 1984.

R. A. Durst, "Analytical Aspects of Chemically Modified Electrodes," 37th

Annual Summer Symposium on Analytical Chemistry, NBS, Gai thersburg , Ml,

June 12, 1984. Invited

S. A. Wise, "Standard Reference Materials for Urban Air Partin-'

Matter—Characterization and Uses," Fourth Symposium on Environ-*

Analytical Chemistry, Brigham Young University, Provo, UT, Jun*- '*,

1984. Invited

103
R. A. Durst, "Chemically Modified Electrode Sensors," Gordon Research

Conference on Synthetic Membranes, New London, NH, June 26, 1984.

Invited

R. A. Durst, "Charge Transport Phenomena in Polymer Film Electrodes," Gordon

Research Conference on Synthetic Membranes, New London, NH, June 28,

1984.

B. Coxon, "Detection and Measurement of the Aldehydro Forms of Aldoses by NMR

Spectroscopy," 12th International Carbohydrate Symposium, Utrecht,

Holland, July 3. 1984.

B. Coxon, "Spectrum Editing of the Carbon-13 and Nitrogen-15 NMR Spectra of

Carbohydrates by the DEPT Technique," 12th International Carbohydrate

Symposium, Utrecht, Holland, July 3» 1984.

B. Coxon, "Determination of Lactose in Dried Milk by Proton NMR Spectroscopy

and by High-Performance Liquid Chromatography," 12th International

Carbohydrate Symposium, Utrecht, Holland, July 5, 1 984.

B. Coxon, "Two-Dimensional DEPT Heteronuclear J-Resolved Carbon- 13 NMR

Spectroscopy of Carbohydrates," 12th International Carbohydrate

Symposium, Utrecht, Holland, July 5, 1984.

J. M. Brown-Thomas , "Chromatography," Satellite ’84 Summer Enrichment Program

for Gifted and Talented Students, Howard University, Washington, DC,

July 16, 1984. Invited

R. A. Durst, "Thermally Crosslinked Polymei—Film Electrodes," UNESCO-NSF

Workshop on Photoelectrochemi cal Processes and Modified Electrodes,

University of California, Santa Cruz, July 23. 1984. Invited

R. A. Durst, "Charge-Transport Models for Polymer-Film Electrodes,"

UNESCO-NSF Workshop on Photoelectrochemical Processes and Modified

Electrodes, University of California, Santa Cruz, July 24, 1 984.

Invited

D. J. Reeder, "Approaches to Standardization in Forensic Electrophoresis,"

First International Symposium on the Forensic Applications of Electrophoresis, FBI Training Academy, Quantico, VA, July 25, 1984. Invited

G. S. Marbury, "Electrochemical/Spectroelectrochemical Study of Copper

Dithiolene Complexes," Second SUNY Albany Conference on Inorganic and

Biochemical Perspectives on Copper Coordination Chemistry, Albany, NY,

July 26, 1984. Invited

D. J. Reeder, "Production and Characteri zation , " Workshop on Standards in

Biomass for Energy and Chemicals, NBS, Gaithersburg, MD, August 1,

1 984.

S. A. Wise, "Factors Affecting Selectivity for Reversed-Phase Liquid

Chromatographic Separation of Isomeric Polycyclic Aromatic Hydrocarbons

on C-]Q Stationary Phases," 188th National Meeting of the American

Chemical Society, Philadelphia, PA, August 30, 1984. Invited

104
R. A. Durst, "Chemically Modified Electrode Sensors for Biocomponents,"

IEEE/EMBS Conference on Frontiers of Engineering and Computing in

Health Care, Los Angeles, CA, September 16, 1984. Invited

3. Committee Assignments

Willie E. May

Chairman, ADABSE, Analytical Workshop Committee

Member, ASTM, Committee D1 9 on Water,

'Committee El 9 on Chromatography

Member, ACS, Environmental Chemistry Division

Board of Directors, Washington Chromatography Discussion Group

Bruce Coxon

Secretary, ASTM, Committee El 3- 07 on Nuclear Magnetic Resonance,

Committee El 3 on Molecular Spectroscopy

Associate Referee, International Commission for Uniform Methods of

Sugar Analysis, Subcommittee 5 on 100 °S Point of Sugar Scale

Referee, U.S. National Committee on Sugar Analysis, Subcommittee 5 on 100 °S Point of Sugar Scale

Member, Program Committee, 12th International Carbohydrate Symposium

Richard A. Durst

Member, Advisory Board, Analytical Chemistry

Member, ASTM, Committee D1 9 on Water

Member, Board of Advisory Editors, Ion-Selective Electrode Reviews

Member, Department of the Interior, Office of Water Data Coordination,

Task Group 5 on Chemical and Physical Quality of Water and

Sediments

Member, Instrument Society of America, Subcommittee SP76.02 on Electrochemical Analyzers

Member, IUPAC, Committee V on Analytical Chemistry, Subcommittee 5 on Electroanalytical Chemistry

Member, NCCLS, Subcommittee on Electroanalytical Methods

Member, NCCLS, Subcommittee on pH and Blood Gases

Diane K. Hancock

Referee, U.S. National Committee on Sugar Analysis, Subcommittee 6 on Quartz Control Plates

Associate Referee, International Commission for Uniform Methods of

Sugar Analysis, Subcommittee 6 on Quartz Control Plates

Laurence R. Hilpert

Member, ASTM, Committee D34 on Waste Disposal

Dennis J. Reeder

Member, AACC, Committee on Standards

Study Group on Cortisol

Study Group on Total Serum Protein

Associate Member, IFCC, Expert Panel on Drug Effects in Clinical

Chemistry

Member, NCCLS, Subcommittee on Total Protein

105
Robert Schaffer

Member, AACC, Committee on Standards

Subcommittee on Cholesterol

Subcommittee on Creatinine

Subcommittee on Electrolytes

Subcommittee on Glucose

Subcommittee on Iron

Subcommittee on Theophylline

Subcommittee on Urea

Subcommittee on Uric Acid

Member, NCCLS, Area Committee for Clinical Chemistry

Subcommittee on Calibration Reference and Control Materials

Subcommittee on Quantities and Units

Subcommittee on Reference Methods and Materials

Member, Council for National Reference System in Clinical Chemistry

*4. Other

a. Seminars

October 12, 1983

October 14, 1983

November 10, 1983

November 10, 1983

December 28, 1983

March 9, 1984

May 10, 1984

June 25, 1 984

June 25, 1984

July 30, 1984

Timothy J. O'Leary, National Institutes of Health,

"RAMAN Spectroscopy of Phospholipid Assemblies".

Thomas McCorkle, LKB Instruments, "Therapeutic Drug

Monitoring (TDM) and High-Performance Liquid

Chromatography (HPLC) —Past and Future".

Jeffrey H. Hurst, National Institutes of Health,

"Biochemical Studies on Two Catecholamine Synthesizing Enzymes".

Herbert Pohl, Pohl Cancer Research Laboratory,

Oklahoma State University, "Biological Dielectrophoresis" .

Dennis C. Shelley, Indiana University, "Sane New

Approaches to Environmental Analysis".

Howard T. Mayfield, University of Alabama, "Pattern

Recognition Techniques for Gas Chromatography".

James L. Meek, St. Elizabeth's Hospital, "Enzymes

Adsorbed to an Ion Exchanger as an HPLC Detection

Device: Application to Acetylcholine Measur ements"

Robert C. Allen, Medical University of South

Carolina, "New Needs for Standar di zation"

Bertold J. Radola, Institut fur Lebensmitteltechnologie und Analytische Chemie, "Approaches to

Standardization in Isoelectric Focusing".

Claude Andrieux, Universite de Paris, "Redox

Catalysis in Solution and on Modified Electrodes".

106
July 31 , 1984

August 7, 1984

August 14, 1984

Isiah M. Warner, Emory University, "General

Discussion on Multi par ameter Luminescence Techniques

for Analytical Measurements".

Isiah M. Warner, Emory University, "Selected

Examples and Applications of Multi parameter

Luminescence Instrumentation"

Isiah M. Warner, Emory University, "Qualitative and

Quantitative Analysis of Multi par ameter Luminescence

Data".

August 1 6, 1 984 - Phillipe Garrigues, Universite de Bordeaux,

"Applications of Shpolskii Spectroscopy for the

Determination of Polycyclic Aromatic Hydrocarbons in

Environmental Samples".

b. Conferences Sponsored

October 23“28, 1983 - W. E. May, Workshop on "A Survey of State-of-the-Art

Instrumental Methods for Chemical Analysis," jointly

sponsored by the National 3ureau of Standards and

the Association for the Development and Advancement

of Black Scientists and Engineers (ADABSE) , National

Bureau of Standards, Gaithersburg, MD.

June 25, 1984 - D. J. Reeder, Workshop on "Electrophoresis

Standardization: Approaches and Needs," jointly

sponsored by the National Bureau of Standards and

the Electrophoresis Society of the Americas,

National Bureau of Standards, Gai thersbur g , MD.

c. SRM Certif ication/Information Values

1) SRM 41c, Dextrose

2) SRM 909, Human Serum

3) • SRM 1543, Gas Chromatography/Mass Spectrometry Pi Standard

4) SRM 1 549, Non-Fat Dry Milk

5) SRM 1580, Organics in Shale Oil

6) SRM 1584, Priority Pollutant Phenols in Methanol

7) SRM 1587, Nitro-PAH in Solvent

8) SRM 1 61 4, Dioxin in Solvent

9) SRM 1 650, Organics on Diesel Soot

10) SRM 1821a, Ethanol in Water

Perf ormance

107
IV. Gas and Particulate Science Division

Harry L. Rook, Chief

Alan Fried, Deputy Chief

A. Division Overview

The Gas and Particulate Science Division conducts research leading to

(a) improved analytical methods for quantitative electron, ion, and photon

microanalysis; (b) improved quantitative x-ray fluorescence analyses; (c)

improved measurements of gaseous species in the atmosphere and in specially

prepared gas mixtures; and (d) the preparation and certification of standards

for measurement quality assurance in analytical chemistry. The Division

responds to the measurement and standards needs of other Federal Agencies,

industrial organizations, universities, and state and local governments. The

Division’s programs are carried out by four groups with the research effort

divided approximately equally between the two general areas of gas analytical

research and microanalytical research.

For the past four years, the Division has been conducting research in

compositional mapping with program funds from the Director’s Competence

Building Program. The goal of this research is to develop quantitative

analytical methods for the determination of chemical features on a micrometer

spatial scale. This year substantial progress has been made in quantitative

compositional mapping, utilizing new capabilities in automated digital image

analysis. The system devised for image transfer and analysis for the

analytical electron microscope (AEM) was developed in the Microanalysis

Research Group to fulfill requirements which could not be met by any commei

cially available system. Initial testing of the system has demonstrated the

capability of transmitting image arrays as large as 512 x 512 pixels derived

from any of the image capabilities of the AEM. Image processing software for

the system has been developed by Group members which allows the superposition

of multiple images such as those from electron and ion beam instruments.

Distortions often exist in individual images due to the fundamental characteristics of the optics in each instrument. To overcome this problem, an image processing technique is under development that can automatically

recognize comparable features in different images of the same field of view

and then correct the distortions to bring individul features of the images

into registration. As a result of this research, data from two different

instruments with different capabilities can be combined to enhance the

ability to calculate elemental or isotopic ratios for a given particle or microscopic feature. In related research, the Cameca IMS-3F ion microscope

has been interfaced with a commercially supplied image processing system.

Quantitative digital image processing using this system has been evaluated.

Some limitations were found in image processing during background subtraction. Correction procedures with the manufacturer-supplied software are being implemented. The results of these research efforts into digital

processing of chemical images have brought the Microanalysis Research Group

to the scientific forefront of this exciting field.

A second area where major advances have been made is in quantitative

isotopic analysis using secondary ion mass spectrometry. Isotopic ratios

have been determined with total uncertainties of ± O.M percent relative on submicrogram samples. This level of accuracy is comparable to the definitive

108
technique of thermal ionization mass spectrometry on bulk samples and expands

the applicability of high accuracy isotopic analysis to a host of new

samples

Other significant accomplishments of the past year include: the

development of an improved correction procedure for calculating characteristic x-ray fluorescence yields in electron microprobe analysis; advanced

research in elemental depth profiling; the development of analytical procedures for organic mass spectrometry using laser ionization; the certification

of the first series of glass matrix standards specifically designed for the

calibration of electron microprobe instruments; and improvements in the

algorithm for calculation of fundamental parameters in quantitative x-ray

fluorescence spectrometry.

Research efforts in gas analysis and atmospheric chemistry have focused

on two major areas: (a) 'trace and ultra-trace gas measurements and standards

and, (b) the development of a definitive mathematical method for the calculation of lower limits of detection of radionuclides in environmental samples.

The results of the latter research, as detailed in a comprehensive document,

will be used by the Nuclear Regulatory Commission to revise its regulatory

reporting procedures for the detection of radioactive effluents from nuclear

power facilities.

Significant progress has been achieved this past year in trace and

ultra-trace gas measurement research. A new calibration approach for diode

laser spectrometry has been developed and evaluated for measurements of trace

levels of HC1. This technique, which utilizes independent calibration based

on different molecular concentrations and species, will be expanded to other

important atmospheric gases. Along with changes in analytical methodology,

instrumental upgrades to the diode laser facility were made this past year to

improve measurement capabilities. One example is the addition of a confocal

interferometer to allow diode laser linewidth measurements to be carried out

simultaneously with absorption measurements, thus assuring accurate quantitative results in cases where the laser and molecular linewidths are comparable.

Research also has been carried out in three new challenging gas

measurement areas. The first is a program to develop a calibration system to

generate known quantities of tritium at approximately ambient atmospheric

levels. This calibration system will be used to put world-wide monitoring

data for atomspheric tritium on a common measurement scale. The second

research program is the initiation of efforts to develop stable mixtures of

reactive gases such as SO2 , NO, and NO2 in N 2 at concentrations at or below 1 part-per-billion (ppb). Such standards would be used to provide measurement

quality assurance for tropospheric monitoring programs in NASA, ERA, ar. : NOAA. The third program involves measuring the temperature dependence of

selected band strengths for the halocarbons F— 1 1 and F-12. These molecules

have become increasingly important in model-dependent calculations of

atmospheric warming and in calculations of perturbations to the Earth’s oz:r.~ layer. The effect of temperature on the infrared absorption of in

molecules has not been well measured. These data are critical for accurnimodeling of atmospheric warming. Moreover, such data are needed for a:.ur r.- determinations of F — 1 1 and F-12 concentrations throughout the atmcspn- - requisite for accurate modeling of ozone destruction.

109
An important result of this year’s program with other Federal agencies

such as NASA and EPA has been to develop a program of measurement traceability whereby estimates of precision and accuracy of a chemical measurement

process are obtained and transferred by a system of primary, secondary and

working standards. The traceability system has been adopted in principle by

the Quality Assurance Division of EPA and the Gas and Particulate Science

Division. Traceable standards have been provided for national ozone monitoring and for programs assessing levels of toxic organic gases. The temperature dependent ultraviolet absorption cross-section data obtained for ozone during the past three years is complete and is now ready for distribution.

These data have been proposed by NASA to the World Meteorological Organization as the international standard data set for all international ozone

monitoring programs. These data form the basis for intercomparison of

satellite observations and ozone data derived from the ground level Dobson

network.

Other important programs of the past year include: the development of

four new ppb level multicomponent gaseous organic compound SRM’s and traceable secondary standards; the completion of three new C02~in-Air SRM’s with

certified values for CO 2 , N2 O, and information values for CHu, F— 1 1 and F-12;

the development of a new catalytic methanation system for use in the analysis

of CO and CO 2 ; continued development of a diode laser spectrometer to study

spectroscopic and kinetic properties of reactive atmospheric molecules; and

the certification of over 500 individual SRM’s.

During the coming year, research efforts in compositional mapping will

be expanded to include molecular compositional mapping and complete, threedimensional mapping using the SIMS system. Other research endeavors planned

in the microanalysis group include: extension of image analysis capabilities

by applying digital techniques to conventional transmitted electron images

and by improved image processing algorithms; further refinements of the

isotopic measurement capabilities using ion and laser microprobes; and the

development of an advanced laser Raman microprobe with multichannel detection

capabilities

In x-ray fluorescence, development will continue on the fundamental

parameter approach to quantitative analysis as well as research in preconcentration methodology. Research leading to development and certification

of new SRM's will also be important activities of this group.

Research in the accurate measurement of, and standards development for,

trace and ultra-trace atmospheric constituents will continue to be the lead

component of the long-range plans for both the gas metrology and atmospheric

chemistry groups. Specific research areas planned for the upcoming year

include: continued development of sophisticated lineshape and fitting

algorithms for accurate gas concentration measurements using a diode laser;

improved measurements of infrared band strengths of selected molecules by

FT-IR and diode laser spectroscopy; application of chemometrics to important

analytical problems; more accurate measurements of the absolute ozone absorption cross-sections at the wavelengths of several ultraviolet mercury

lines; continued development of inorganic and multicomponent toxic organic

gas standards; and continued research on the preparation, analysis and

stability of ultra-trace gas mixtures.

no
1 . Microanalysis Research Group: Overview

The Microanalysis Research Group carries out research to advance the

development and application of microbeam analysis techniques for the chemical, crystallographic , and morphologic characterization of matter on the

micrometer and sub-micrometer spatial scale. The analytical techniques

utilized are based on primary (excitation) particle beams of electrons, ions,

or photons, and secondary (analytical) signals of x-rays, inelastically

scattered electrons, inelastically scattered photons, and ions. The techniques include electron microprobe analysis, scanning electron microscopy,

electron energy loss spectrometry, secondary ion mass spectrometry, and laser

microprobe mass analysis. Research on each technique is conducted with the

objectives of (1) advancing understanding of the basic physics of sample

excitation and attenuation of the secondary radiation; (2) developing methods

of quantitation; (3) producing standards and measurement techniques as a means of disseminating developments; (4) developing improved compositional

mapping techniques; and (5) applying results of the research to the study of

specific analytical problems to support NBS and other government agency

missions

During this past year, advances have been made in each of the major

areas of research activities of the Group. In electron beam analysis, the

implementation of digital imaging has been accomplished on both the electron

probe microanalyzer (EPMA) and the analytical electron microscope (AEM). The

system devised for the AEM has been developed as an original hardware/

software system by Group members to fulfill a need which could not be met

with any system that is commercially available. Initial testing of the

system is now underway and has demonstrated its capabilities of transmitting

image arrays as large as 512 x 512 pixels derived by scanning transmission

electron imaging, scanning secondary electron imaging, scanning electron

diffraction, and x-ray area scanning. Important image processing software

has been developed which addresses fundamental problems in compositional

mapping. A major problem exists when information from different mapping

instruments needs to be combined, such as electron beam and ion beam images.

Distortions exist in the imaging process of each due to the individual characteristics of their optics. An image processing technique is under development which can automatically recognize comparable features in two images of

the same field produced by different techniques and then calculate the cor- rections which must be applied to bring the images into registration . A second area of image processing development for the AEM concerns the implementation of an algorithm which can accurately characterize linear structures

such as those used for magnification calibration.

In the area of ion beam analysis, the Cameca IMS-3F ion microscope has

been upgraded by the addition of a primary-beam mass filter. In addition to

providing specific selectivity for the variety of ion species produced by the

duoplasmatron ion source, the mass filter also permits simultaneous mounting

of the cesium ion source. This feature greatly improves the utility of the

cesium ion source, which has important applications to problems that cannot

be solved using ions derived from the duoplasmatron. Examples of then ^ applications include the analysis of gases in metals, certain species cf

interest in semiconductors (As in Si, P in GaAs ) , and detection of car k •

The image processing system of the ion microscope has been used for the •

. of crystallographic effects in secondary ion emission and to assess tn<- r-
of trace elements in modifying the secondary electron emission characteristics of reaction-bonded silicon carbide. Studies of isotopic analysis with

the ion microscope have demonstrated its capability of precise and accurate

measurements of isotopic ratios with a dynamic range of 100,000 to 1.

In the area of photon beam analysis, the measurement capabilities of

the laser microprobe mass analyzer (LAMMA) have been extended to the measurement of isotopic ratios with a dynamic range of 500 to 1. This has been

accomplished by developing a correction algorithm to compensate for the

non-linearity of the LAMMA detection system. Useful isotopic ratio measurements have been measured for sample masses as small as 0.1 pg , in which

accurate values were obtained by making repeated analyses of the same target

by the use of grazing incidence excitation. The combination of AEM and LAMMA

has been applied to study isotopic distributions within particles of complex

mineral systems, such as zircons.

A comprehensive study of instrumentation for laser Raman microanalysis

has been completed. This study involved careful comparison of a scanning

single channel instrument originally developed at NBS with an advanced

multichannel solid state detector instrument developed with NBS collaboration

at an Other Agency laboratory. Beam sensitive materials were studied to assess the improvements which could be realized by minimizing the radiation

dose to which the sample is subjected during analysis. The improvements in

performance were quite pronounced, and the experience gained in implementing

the prototype will be used to develop an advanced instrument at NBS.

Future Plans :

Future plans in microanalysis research focus on advanced compositional

mapping, high accuracy microprobe measurements, and new SRM development. In

the area of electron analysis, the digital imaging system will be extended to

include digitization of the conventional transmitted electron images and

diffraction patterns. This will greatly extend our analytical capabilities.

Image processing algorithms will be developed for direct deconvolution of

electron diffraction patterns from the fundamental characteri sties of the

pattern with minimal operator intervention. The electron energy loss signal

will also be utilized for compositional mapping images. Investigations into

low-energy microanalysis of solid specimens will be initiated.

Ion beam analysis by secondary ion microscopy will be extended to

achieve quantitative analyses, both laterally and in-depth, to realize

complete three-dimensional compositional mapping. Further refinenent of the

isotopic measurement capabilities of the ion microscope will be made by the

addition of electrostatic peak switching to augment the magnetic peak

switching currently in use.

In the area of photon beam analysis, work will begin on the development

of an advanced laser Raman microprobe with multichannel detection capabilities and the possibility of molecular compositional imaging. The fundamentals of quantitation of simple molecular mixtures will be investigated.

Dale E. Newbury, Group Leader; Adville A. Bell, David S. Bright, Edgar S.

Etz, Robert A. Fletcher, Ryna B. Marinenko, Raymond L. McKenzie, Robert L. Myklebust, Partick J. Sheridan, David S. Simons, John A. Small, Brian R.

Stallard, Eric E. Steel, Barbara B. Thorne.
2 . X-ray Fluorescence Group: Overview

The X-ray Fluorescence Group performs research on: (1) fundamental

parameter data reduction methods to increase the accuracy of quantitative

analysis of thin and bulk samples; (2) improved sample preparation techniques

to increase analytical sensitivity; and (3) development of nondestructive

sample preparation techniques for increased analytical speed and reduced

cost. A major portion of the work also consists of the quantitative analysis

and homogeneity testing of new, and renewal SRM’s using a high performance,

automated, wavelength-dispersive x-ray spectrometer.

During the past year, we have continued research to improve the

accuracy of a fundamental parameter computer program for quantitative x-ray

analysis. A significant portion of this program includes the N3S algorithm

for calculating the output spectral distributions of x-ray tubes on which we reported last year. Using this program, the results of analysis of several

specimen types have been compared with those obtained with another fundamental parameter program, NRLXRF. A research paper on this intercomparison for

alloys, pressed powders, and fused specimens is being prepared for publication. Modifications made to the computer program include options for

different sample preparation conditions and improved algorithms for

calculating mass absorption coefficients.

Several "natural matrix" materials such as clays, ores, and coals were

measured to characterize elemental homogeneity and composition leading to the

certification of the materials as SRM's.

The laboratory is presently being refurbished to accomodate expanded

research efforts in preconcentration sample preparation methods for trace

element analysis. These methods focus on the use of thin substrates containing immobolized chelating functional groups that vary in their specificity

for different metals. Equipment has been purchased and assembled for

performing automated preconcentration of trace elements in such samples as mineral materials and biological samples important to the Standard Reference

Material Program.

The fabrication of a limited number of new thin glass films for

calibration of x-ray spectrometers has been initiated this year. These films

will be used as research materials by the Environmental Protection Agency and

will augment the NBS-SRM thin film standards 1832 and 1833 now available.

Upgrading of the energy-dispersive x-ray spectrometer has continued.

Acquisition of a high performance desk-top X-ray generator for increased

instrument reliability is planned. The recent availability of these compart

units has made this upgrade feasible at relatively low cost.

The activities of the X-ray Fluorescence Group for next year will fall

into the following categories: (1) evaluation with standard data sets of the

fundamental parameter approach to quantitative x-ray analysis; (2) rese-.r”

in preconcentration methodology for increased analytical sensitivity ftrace element analysis; (3) characterization of the elemental homogor. • :ty

113
composition of new SRM materials leading to their certification as NBS-SRM’s;

and (*0 development of new thin film x-ray SRM's.

Peter A. Pella, Group Leader; Anthony A. Marlow, John R. Sieber, Gerald A.

Sleater, Guang-Yi Tao, and Kevin R. Garlow.

3 . Atmospheric Chemistry Research Group: Overview

The Atmospheric Chemistry Research Group conducts research on measurement techniques for ambient concentrations of atmospheric species in both

gas and particle (liquid and solid) phases. This research includes the

development of sampling/collection techniques, in situ and laboratory

analytical methods, micro-sample preparation and analysis methods, and application of mathematical statistics. A primary objective of this research is

the extension of existing, and the development of new, analytical techniques

for the detection of trace and ultra- trace level atmospheric constituents.

Research has continued this year on a long term effort to develop and

characterize sensitive and selective laser-based spectrometri c techniques for

the analysis of trace reactive atmospheric gases. Photothermal and tunable

infrared diode laser techniques have been used for this purpose. As in the

past, significant emphasis has been placed on verifying the accuracy of the

trace gas standards employed in these studies. To this end, a new calibration approach, using a known concentration, non-reactive, reference gas, has

been assessed successfully and employed in the calibration of a tunable diode

laser system for HC1 measurements. A computer modeling analysis was developed as part of this procedure to account for response differences between

the reactive HC1 sample gas and the non-reactive reference gas. This new calibration approach is currently being expanded to include other reactive

molecules and presents some significant advantages in cases where known

sample gas concentrations cannot be readily generated. Additional progress

has been achieved this year in the tunable diode laser research program.

Several instrumental upgrades have been added to the existing facility to

enhance system versatility and stability as well as the resulting accuracy of

quantitative measurements on trace gas species. One such purchase, a confocal interf er ometer , now allows direct measurement of the diode laser

linewidth. With this capability, accurate quantitative absorption measurements can now be carried out in cases where the laser linewidth is a significant fraction of the molecular linewidth under study.

Significant progress has been achieved this past year in the area of

environmental carbon research. Techniques have been developed and applied

for measuring carbon and carbon isotopes in tropospheric gases and particles.

Through the use of Accelerator Mass Spectrometry (AMS), 1 measurements can now be made on samples containing as little as 50-100 yg of carbon. This

represents an improvement of more than a factor of 100 compared to other

detection methods and is crucial for a number of atmospheric chemistry

studies in which concentrations of climatically significant and toxic

carbonaceous species limit the sample size to well below the milligram range.

Work completed in this area and carried out jointly with the University of

Arizona has provided reliable atmospheric measurements from a variety of sources. This work has also led to a chara cteri zation of the overall

chemical and isotopic blank in AMS measur ements . An additional cooperative

study with the Norwegian Institute for Air Research and the Central Institute

for Industrial Research has resulted in some very significant conclusions
concerning long-range transport and the nature of local sources. This

information is derived from multidimensional patterns among 1 concentrations in particles, meteorological conditions and the concentration of

certain inorganic and organic constituents.

Such multidimensional data interpretation is but one of a number of

applications where mathematical and statistical techniques have been applied

this past year to analytical data sets. Other important applications of

chemometrics include the assessment of detection limits in analytical and

nuclear chemistry and the design and improvement of the analytical measurement process. Using these techniques, a two-year study on the lower limit of

detection of raaiological effluents from nuclear power plant operations has

been completed, and a detailed document has been prepared for the Nuclear

Regulatory Commission. This document represents the first comprehensive,

unified, self-consistent treatment of detection limits for the nuclear

utility industry. It provides theoretical background as well as practical

guidance for the design and evaluation of nuclear measurements.

In the area of ozone research, final results for the ultraviolet

absorption cross-sections in the Hartley and Huggins bands as a function of

temperature have been prepared for distribution. Comparisons with other

laboratories indicate agreement to within 3 % for the absolute values and to

within 1i for the relative values. The International Ozone Commission, at

its Quadrennial Symposium in September 1 98-4 , considered and adopted the NBS

results as the standard reference values to be used in the analysis of

atmospheric observational data. Collaboration with EPA in their efforts to

establish an ozone monitoring network has continued this past year. Additional photometers based on the NBS standard were constructed, and plans are underway to establish a protocol for the regular maintenance and

re-certif ication of the network instruments relative to the NBS primary

standard.

The focus of research activities for the next year will include: (a)

continued development and application of photoacoustic and tunable diode

laser detection techniques for trace and ultra-trace atmospheric gases; (b)

development of more sophisticated lineshape and fitting algorithms for

accurate diode laser absorption and pressure-broadening coefficient determinations; (c) kinetic measurements of transient species utilizing diode laser

spectroscopy; (d) further application of chemometrics in the investigation of

problems highlighted in the NRC document, in the study of the design and

evaluation of multidimensional data sets, and in the development of simulated

numerical data bases for interlaboratory quality assurance; (e) extension cf

the sensitivity of 1 detection techniques in environmental samples a f-.-w micrograms in size for application to the investigation of sources of atmospheric mutagens; (f) extension of ozone absorption cross-section measurements to longer and shorter wavelengths; and (g) significant improvement ir. the accuracy of the determination of the absolute ozone absorption crc.::- sections at several wavelengths of ultra-violet mercury lines using m

spectrometry

Lloyd A. Currie, Group Leader; Arnold M. Bass, Alan Fried, George A. K 1 : : •.

,

James E. Norris, Jeanne M. Sullivan, and Anne C. Trevey.

115
4 . Gas Metrology Research Group: Overview

The Gas Metrology Research Group conducts fundamental and applied

research leading to (a) the improvement of measurements for ambient, trace,

and ultra-trace gas analysis, and to (b) the development of accurate and

stable standards for the analysis of a wide variety of inorganic gaseous and

organic vapor mixtures ranging in concentrations from the percent to the 1 ppb level. Reliable inorganic and organic gas standards are developed to

provide data quality assurance in world-wide measurements of gaseous species.

Basic analytical research and rigorous measurements are carried out to ensure

that the resultant standards are both accurate and stable. Research also is

carried out to improve the scientific understanding of causes of chemical

instability of gas mixtures, and to more fully characterize spectroscopic and

chromatographic detection, and basic properties of gas molecules that may

affect accurate gas analysis or the certification of gas standards.

The Group directly responds to, and interacts with, gas measurement and

standards needs of other agencies, industrial organizations, and standards

setting-bodies at the local, state, and national levels; provides advice and

guidance to the private sector as needed; and addresses gas measurement needs

on a world-wide basis. Utilizing its unique capabilities, the Group also

performs a limited number of gas analyses for external organizations.

Activities and accomplishments of the Group during the past year

include: the development of additional standards to provide data quality

assurance in long-term world-wide measurements conducted to quantify changes

in global atmospheric CO 2 levels and to assess their possible impact on global temperature and climate; the development of multicomponent, trace

organic gas mixtures to provide data quality assurance in national measurements made for toxic, volatile organics in urban and industrialized areas and

in hazardous waste incineration operations; the initiation of calibration

systems and standards for the quantification of atmospheric tritium levels

and the magnitude of other ultra-trace species which contribute to dry acid

deposition; the completion of a number of gas SRM’ s and special gas analyses;

the development of several analytical systems for improving gas analysis; and

the improvement of computing capabilities for the treatment of analytical

data. A brief description of these activities and accomplishments follow.

Three new C0 2 -in-Air SRM’s have been completed having nominal certified

C0 2 concentrations of 305, 3^0, and 375 ppm (by mole) and N 2 0 concentrations

of 270, 300, and 335 ppb (by mole). Representative information values for

methane and for F-11 and F-12 halocarbons also are provided for these new standards, making them the most complex atmospheric gas standards developed

to date. The first C0 2 concentration data also have been determined in these

standards using a new isotope dilution - mass spectrometry technique developed by members of the Inorganic Analytical Research Division. Other C0 2 data

have been provided by an independent i ntercomparison carried out under

contract with the Scripps Institution of Oceanography.

A multi-year EPA-sponsored program for the development of NBS-traceable

single and multicomponent toxic organic gas mixtures has continued. We

accomplished the following: (1) demonstrated one-year stability and accuracy

of a 3~12 ppb five-component audit mixture; (2) prepared several special

audit mixtures for EPA's use in evaluating the analytical capabilities of

contract laborator i es ; (3) prepared and evaluated several nine-component and
five-component gas mixtures in the low ppb range for EPA's use; (4) developed

a special five-component deuterated toxic organic mixture for EPA's use in

evaluating uncertainties in blank levels in Tenax traps; (5) prepared and

evaluated multicomponent toxic organic mixtures at the one ppD level; (5)

prepared standard toxic organic mixtures to assist the development of ID-MS

methodology by the Organic Analytical Research Division; and (7) completed

the first full set of analyses on the first multicomponent toxic organic

SRM’s (two SRM’s containing benzene, toluene, chlorobenzene, and br otnobenzene

at nominal concentrations of 10 ppm and 0.25 ppm by mole, respectively). Two

technical papers were presented on the preparation of multi-component toxic

organic standards, and one technical paper was presented describing the

accuracy of the special mi crogravimetric technique used for preparing these

standards

During the past year, work was initiated in three new challenging

areas. One of these has involved the evaluation of a system for the collection and measurement of levels of tritium in the atmosphere and has primarily

focused on the development of a stable source of tritium for _in situ calibration of the collection system. Accomplishments on this latter activity have

included: the design, fabrication, and evaluation of a dynamic dilution

system for quantitatively adding tritium to the incoming air stream flowing

into the collection system; and the evaluation of potentially stable,

accurate sources of tritium, based on the use of a tritium-doped gas cylinder

or the use of an electrolytic generating system for hydrogen tritide (HT : and the development of capabilities for low-level tritium measurements using

gas proportional counting. Work initiated in the other two areas has focused

on research aimed at the development of ultra-trace standards for the reactive gases SO2 and NO2 (EPA dry acid deposition studies), and on research to

measure the temperature dependence of band strengths for halocarbons Freon-11

and Freon-12 at relevant atmospheric temperatures.

In addition to the above activities, a number of accomplishments have

been achieved in our SRM program. These include: the development of new, or the reissuing of existing, gas SRM’s; the re-certification of gas SRM’s

requested by various SRM users; and special analyses.

A total of 61 SRM’s received from 12 different SRM users were recertified, covering the entire range of constituents. Special analyses con- ducted during the year include: the analysis of binary mixtures of CO, CO 2 , and propane in N 2 for use by the State of California as primary calibration

standards for their auto exhaust emission analysis IM program; the analysis

of calibration mixtures for the State of Maryland to clarify anomalous

results obtained by State auditors at inspection sites in the State's new auto exhaust emission IM program; and the analysis of a variety of gas

mixtures for their use as motor vehicle exhaust calibration standards by the

Japan Automotive Manuf actur ers Association. Special analyses also were performed for the U.S. Navy and their Primary Gas Standards Program.

Miscellaneous activities during the past year included: (a) the des.gr'

and evaluation of a repetitive cryogenic trapping system for the analysis •'f ultra-trace gases; (b) the redesign and application of a catalytic me* • - ation system for the analysis of CO and CO2 in air mixtures; (c) the ins* - lation of a new computer for the Group's Fourier-Transf orm IR spectrcc-'

system and its direct coupling to the Division's VAX computer; and

coupling of the Group's computer systems to the NBS net.

117
Future activities of the Group will involve: (a) the development of

C0 2 in air standards at 100 and 1000 ppm to provide wide-range calibrants for

measurements of atccnspheric C0 2 ; (b) continued development in toxic organic

standards (including the development of mixtures at 1 ppb, traceable audit

mixtures for hazardous waste incineration, completion of two ^-component

toxic aliphatic organic mixtures as SRM’s, and the addition of GC-MS capabilities); (c) the evaluation of electrochemical methodology (initially,

amperometric titration) for the analysis of polar (e.g., S02 ) gases; (d) an upgrade of the Group's existing gas mass spectrometer ; (e) the development of

standards for natural gas, certified for total composition and for BTU

heating value; and (f) continued research on the preparation, analysis, and

stability of ultra- trace gas mixtures.

Two guest scientists have recently joined the Group for one-year

appointments: Francois Abbo (from the Center for Research and Development,

L'Air Liquide, Pairs, France) as a Research Associate interested in the

instability of reactive gases (e.g., NO) and in the preparation of stable,

ultra-trace mixtures of such gases; and Zhong-tao Cai (frcm the Shanghai

Institute of Ceramics, Shanghai, People's Republic of China) as a Guest

Worker interested in the analysis of ultra-trace levels of gases entrained in

ceramic materials.

Walter L. Zielinski, Jr., Group Leader; Barry C. Cadoff, William F. Cuthrell,

William D. Dorko, James W. Elkins, Ernest E. Hughes, Particia A. Johnson,

Rudolph von Kelly, Gerald D. Mitchell, W. Robert Miller, Richard D. Myers,

George C. Rhoderick, and James E. Suddueth.

118
B. Selected Technical Reports

(Gas and Particulate Science)

1 . Development of an Accurate Calibration Standard for the Measurement of

Atmospheric Tritium (15330)

E. E. Hughes and W. R. Miller

Accurate measurement of temporal increases of tritium in the atmosphere

can serve as clues to identifying otherwise unpublicized nuclear events of

anthropogenic origin. The accuracy of identification depends to a great

extent on the accuracy of the individual measur ements , which in turn, depends

on the reliability of the calibration of the sampling-measuring system

currently being used for atmospheric tritium measurements. To address the

needs for verifying the reliability of such meas ur ements , a project was initiated earlier this year which focuses on two areas of reliability of the

sampling-measuring system, namely, calibration and performance.

Portable calibration systems for the sampling-measuring system are being developed and evaluated, based on the use of a stable source of tritium

and a characterized dilution system for coupling the tritium source with the

sampling-measur ing system. Two approaches to the establishment of a stable

tritium source are under investigation: (1) a gravimetrically-prepared gas

cylinder mixture of tritium and hydrogen; and (2) an electrolysis ceil in

which tritiatsd and normal water will be converted under controlled conditions to a mixture of tritium and hydrogen. The overall reliability of the

sampling-measuring system also will be assessed by evaluating its individual

components, namely its mechanical pumps, flowmeters, scrubbers (for removing

atmospheric water from the sampled air) , and the catalytic reaction chambers

for converting atmospheric tritium to tritiated water).

Extensive tests with the electrolytic method using a mixture of D 2 O and

H 2 O showed a variability of HD generation over a 24-hour period that was similar in magnitude to the variability (2$) in the measurement system (mass

spectrometry) being used, indicating that the electrolytic system produces a stable generation rate of HD. In addition, a portable and simple dilution

system has been designed, assembled and tested, affording measured concentrations of test gases within 2 % of those predicted from the flow rates and the

initial concentration of the test gases. This dilution system, coupled with

the electrolysis cell, should serve as a useful source of tritium if the

results obtained with the dilution system and electrolysis cell are determined to be valid for mixtures of tritium and hydrogen. An apparatus for

assessing the capacity and efficiency of the water vapor scrubbers in the

sampling-measuring system has been assembled and several tests have beer

completed. The existence and extent of isotopic discrimination in the system,

is being studied using hydrogen-deuterium mixtures or mixtures of light ant

heavy water. Most of these experiments are still in progress.

The successful accomplishment of this research will provide the capability for _in situ calibrations of field measurements of atmospheric trip.

and a quantitative assessment of changes in its atmospheric concentration.

119
2 . Assessment of Uncertainties in Gravimetrlcally -Prepared Toxic Organic

Gas Mixtures in the Part-Per-Billion Range (15330)

G. C. Rhoderick, W. F. Cuthrell, and W. L. Zielinski, Jr.

A program supported by EPA's Environmental Monitoring Systems

Laboratory to develop standards for air pollutants was initiated at NBS

several years ago to address a critical need for accurate, stable gas

standards for trace levels of volatile, toxic organic species. The establishment of this program was driven by a rapidly-expanding, uncorrelated

analytical data base of measurements of such species in the ambient atmosphere. Recently, this program has necessitated the extension of the range of

concentrations from the part-per-million level to the intermediate-to-low

part-per-billion level. This extension required that modifications be made to

the microgravimetric method used for the preparation of part-per-million

level standards and that work be undertaken to assess quantitatively the errors associated with the preparation and analysis of standards in the

part-per-billion range.

The modified procedure involved a substantial reduction in the size of

the sample capillary tubes into which single organics were weighed and

subsequently heat-sealed. The overall preparation procedure involved a controlled introduction of the individually-sealed organics into an evacuated

and weighed cylinder, pressurizing the cylinder (to 1 600 psi or more) with

clean, dry, preanalyzed nitrogen, and analysis of the organic analyzes in the

gas mixture by GC using previously prepared and characteri zed organic gas

mixtures. To assess the preparative and analytical errors associated with

the assigned concentration values of the organic analytes, a set of six

cylinder mixtures was prepared. The mixtures each contained benzene, vinyl

chloride monomer, carbon tetrachloride, chloroform, and tetrachloroethylene

,

in a nitrogen matrix, ranging in concentration from 3 to 150 ppb. Agreement

between gravimetri cally-calculated concentrations and concentrations determined by GC analysis against previously-prepared and characterized mixtures

of the 5 analytes ranged from 0.5? (for benzene) to 3.6? (for tetrachiorcethylene). Separate estimates were made of the individual errors contributing to the overall error of the preparation procedure and to that of the

analysis procedure. The total errors for the preparation and analysis

procedures were similar in magnitude (ranging from approximately 0.5 - 5?,

depending on the organic in question). The two errors were subsequently

summed in quadrature to obtain an assigned uncertainty to the concentrations

of each of the analytes in each of the six mixtures. The assigned uncertainties (95? confidence limit) ranged from 0.4 ppb for a 24.5 ppb concentration

of vinyl chloride monomer (i.e., 1.6?) to 1.6 ppb for a 13.6 ppb

concentration of tetrachloroethylene (i.e., 11.8?).

The establishment and relatively low levels of the errors (at 95?

confidence) estimated for these low ppb level standards places a statistically-vali d margin of accuracy on the concentrations of toxic organic

species such that they can be reliably used as traceable standards for the

calibration of measurements in field studies conducted nationally. Additional studies have demonstrated that such mixtures have a concentration

stability of more than a year.
3 . Measurements of the Temperature Dependence of Selected Infrared Band

Strengths of Halocarbons F— 1 1 (CClqF) and F-12 (CCIpF?) (15330)

J. W. Elkins and R. L. Sams

The infrared (IR) properties of the halocarbons F— 1 1 and F-12 have

received considerable interest due to their strong IR absorption in the

"atmospheric window" region of the electromagnetic spectrum where trace

components of the atmosphere are predominant absorbers of re-radiated energy

from the earth's surface. Long-term releases of these halocarbons into the

atmosphere from anthropogenic activity may increase the earth's global

temperature (the so-called "greenhouse effect"). Recent theoretical calculations estimate that the predicted warming effect from an increase in concentration of a few parts per billion (ppb) for both F— 1 1 and F-12 could lead to

a "greenhouse effect" which would be approximately 1/3 that predicted by a doubling of the current carbon dioxide concentration (ca. 340 ppm). 3oth F—1

and F-12 are more effective "greenhouse" absorbers per molecule than carbon

dioxide. These halocarbons absorb in a more linear region of Beer's law than

CO 2 and away from other interfering IR absorbers in the atmosphere. To

adequately describe the warming effect caused by these halocarbons, accurate

knowledge of their IR band strengths and band positions is required for

theoretical model calculations. Extremely few measurements of these parameters for F— 1 1 anG F-12 exist in the literature. Furthermore, most of the

band strengths are at low instrumental resolution (>0.25 cm

-1

) and at room temperature (296 K). The former can give erroneous values of the band

strength

Climate modelers need to know the band strength at more than one temperature, due to the variations of temperature in the atmosphere. There

are three possible empirical relationships for the temperature dependence of

the apparent band strength (Sy): a square root dependence on the temperature; no dependence; and an inverse dependence. The differences in these

relationships and the effect of the temperature dependence on the band

strength can be significant. For example, if the atmospheric concentration

of F— 1 1 were to increase from the present value of 0.2 to 1 ppb, and F-12

from 0.4 to 3 ppb, the calculated warming effect would vary from +0.42 K

(square root dependence) to +0.63 K (inverse dependence). In comparison,

doubling the . CO 2 concentration to 680 ppm would result in a warming of

+2.0 K.

A new research effort recently was initiated to measure the band

strengths of both halocarbons F— 1 1 and F-12 using a Fourier Transform

Infrared (FT-IR) spectrometer and temperature controlled gas cells at four

different temperatures (220, 235, 250, and 273 K) , and to reduce the uncertainties of our previous measurements at 296 K. This work is being jointly

supported by the Chemical Manuf acturers Association (CMA) and NBS. Tr.e first

phase of this work, which involves the construction of low temperature gar

cells, is near completion. A faster mini-computer also has been installed t reduce the computation times for the fast Fourier transforms from 35 m . r

* • min and to enhance data analysis. Following completion of the low t-‘-; • - ture cell, measurements at the described temperatures will be conduct' -

: compared to literature values where they exist.

121
n. Development of a Cryogenic Preconcentration Technique for the Analysis

of Ultratrace Constituents in Gas Mixtures ( 15330)

B. C. Cadoff

Preconcentration techniques have been widely used to analyze organic

vapors in workplace atmospheres and ambient environments. Such techniques

have traditionally used solid or liquid phase sorbents for the concentration

of such vapors and are often plagued with errors due to incomplete collection

or recoveries of the vapors to and frcm the sorbents used. Other drawbacks

of these techniques have been the absence of clearly-defined precision and

accuracy assessments and inadequate assessment of flow rate and volume

measurement errors. Cryogenic preconcentration techniques on the other hand,

should, in principle, allow for the accurate analysis of organic vapors down

to the part-per-trilion level and improve the accuracy and precision of gas

analysis at the part-per-billion level.

A gas chromatograph (GC) equipped with a flame-ionization detector was fitted with a gas sampling valve connected to a stream splitting valve which

can direct the sample either directly into the GC or into a cryogeni callycooled trap. In one mode of sample introduction, the contents of the gas

sampling valve are directly flushed into the GC column. Alternatively, the

sample frcm the gas sampling valve can be directed to the cryo-trap for

concentration prior to GC introduction. Evaluations were carried out with

samples of benzene in nitrogen at concentrations of ^6, 10, and 0.25 ppm. The

cryo-trap preconcentrator is a small loop of 1 /8-inch stainless-steel tubing,

maintained in a bath mixture of dry ice-ethanol. After the sample is

collected in the cryo-trap, the loop is isolated frcm the carrier gas stream

and is gently heated in a 30 °C water bath. The vaporized sample concentrate

is then connected to the carrier gas stream and flushed into the GC column

for analysis.

The results to date indicate that the relative precision of the

cryogenic preconcentration method is comparable to the standard method of

direct GC analysis within a few tenths of a percent. It was also determined

that, when several samples are collected in the cryo-trap, the GC peak areas

of composite samples are simple multiples of the peak area obtained frcm a single sample.

Further work is continuing on the assessment of the precision and

accuracy of this method. The system also will be evaluted to assess the

accuracy of collecting large samples ( 1 00 mL to 1 L or more) so that application can be made to the analysis of gases and vapors at, and below, the ppb

level

5. The Investigation of the Long-Term Stability of Tetrachloroethylene

Permeation Tubes (15530

G. D. Mitchell

The accurate preparation and characteri zat ion of stable gas standards

are essential for meaningful data quality assurance in the development,

evaluation, and practice of analytical methods for gas analysis. In recent

years, it has been recognized that a major deficiency exists in the availability of reliable standards for analysis of volatile, hazardous organic
species present at, and below, the part-per-million level in the atmosphere.

Such standards are typically provided as compressed gas mixtures in metal

cylinders and as liquids in permeation tubes. The latter type cf standards

complement the former in offering the capability of generating a range cf

very lew concentrations not generally available in compressed gas mixtures in

cylinders. Compressed gas mixtures of benzene and tetrachloroethyiene have

been certified as SRM's, and an SRM permeation tube for benzene also is

available. A related project sought to characterize the quantitative perfor- mance of permeation tubes containing tetrachloroethyiene, an envircnnentallyimportant volatile hazardous organic which has been used extensively in the

dry-cleaning industry.

Gravimetri cally-det ermined permeation rates of tetrachloroethyiene

permeation tubes from a common batch have been followed at 25 °C for a period

of more than 2.5 years. The permeation rate was observed to gradually

increase over tne first 15 months of this study, following which, a steacy-

_n crease t: ess

• W ^ V“*

, * i 12 r elative per year was attained. 'ubes

from the same batch that were studied for the first time after 16 months of

the study • V-* - 1 W Vv snow the higher permeation rate increase evidenced by tubes

in the first 16 months of the study. These results indicated a long-term

stabilization period for the tube material in contact with the permeate. Data

alsc were obtained on a subset of the tubes at 20 and 30 °C; it was observed,

however, that a 2-u week ceriod was necessary before a tube that was carried

through such a temperature excursion became re-equilibrated tc a stable

permeation rate at 25 . The data for the full study were examined by

linear regression analyses to discern the changes in permeation rate and its

stabilization

cf

The results of this study will serve as the basis for t tnese buses as a new tetrachloroethyiene SRM. The nominal

the tetrachloroethyiene is 1 microgram/minute at 25 °C.

he certification

permeation rate

This SRM will be

available for the generation of test atmospheres containing

tetrachloroethyiene and for the calibration cf measurement

quantitative analyses cf ambient air samples containing

trace levels of

methods used in

this hazardous

materi a:

6. Development of an Improved Methanation System for the Analysis of CO

and CO? SRM's (15330)

R. C. Myers

A gas methanation system using a Ni catalyst and coupled to a ga:

chromatograph containing a flame-ionization detector (FID) has been used as one of two possible techniques for the quantitative measurement and certification of CO/N’ 2 , CO/air, COpA^f and CC 2 /sir SRM's. The i_n situ catalytically-produced methane is analyzed by gas chromatography. The N: catalyst,

however, has been found to be susceptible to poisoning by oxygen bur it.

analysis of CO and CO 2 in air mixtures.

In the case cf C02/air samples, this problem can be resolvet r

y

palladium catalyst before the Ni catalyst. The palladium catalyst r- : the oxygen to water which has no effect on the Ni methanation cats:.. • t

the case of CO/air mixtures, however, the palladium catalyst als r---~ Therefore, a new methanation system using GO separation to rer.-ve : by a Ni catalyst was designed for the analysis of CO SP.M’s.

123
In this new design, an automated in-line 10-port gas sampling valve was installed between the end of the GC column and the Ni catalyst bed. The

valve served to inject the sample and vent the eluted oxygen peak, following

which it was switched to allow the eluted CO (or CO2 ) peak to enter the Ni

catalyst bed, with the resulting methane entering the FID. The valve was time-sequenced through a programmable integrator connected to the GC to also

permit repetitive automated sample injections. This mode of operation

ensures that each valve switching operation occurs at precisely the same time

for each sample. Hence, equal treatment of samples is achieved. Using

high-purity carrier and fuel gasses in conjunction with several in-line gas

purifiers, the Ni catalyst system has been operated for a period of over 6

months without any significant signs of deterioration.

The development and establishment of this system has provided a reliable, highly-precise analysis method for the certification of CO/air (and

C02/air) SRM’s.

7. The Development of a System for Analytical Traceability in the State

Motor Vehicle Emissions Testing Program (15330) ~

W. D. Dorko

Many states are implementing motor vehicle emissions testing programs,

referred to by the U.S. Environmental Protection Agency as IM (Inspection and

Maintenance) programs. Such programs require that motorists take their

private vehicles each year to locally-designated testing facilities where the

exhaust gases emitted frcm the vehicle tail pipe are directly tested to

determine levels of carbon monoxide, hydrocarbons , and carbon dioxide. Most

of the testing is carried out with non-dispersi ve infrared analyzers (NDIRs),

which are not absolute instruments and require periodic calibration. Since

the NDIR signal can suffer from interferences frcm other gases being analyzed, the calibration gases are designed to simulate the auto exhaust for

the three gases being measured. To illustrate the magnitude of the measurement problem, the State of California has approximately 7,000 NDIR analyzers

that require routine calibration at least once a week. As a quality assurance check, California has established a program to certify gas companies

that are able to supply quality calibration gases. The NBS Gas Metrology

Group, at the request of the State of California, has provided three sets of

analyzed gas standards to enable California to audit gas companies interested

in becoming certified. This mechanism allows California and other states to

identify quality suppliers of calibration gases, and offers the potential for

IM programs conducted by states throughout the U.S. to be tied to the

analyzed standards provided by NBS.

The need for quality control in state IM programs was demonstrated this

past year in which a state, not requiring calibration gas vendor certification, experienced difficulties in interpreting data that the state IM Quality

Assurance group had obtained. This state suspected that its calibration

mixtures, obtained by low-cost bidding, were incorrect, and requested NBS

assistance. Two cylinders containing a propane calibration gas mixture that were being used for hydrocarbon emission testing and were presumed to have

identical propane concentrations (nominally, 2500 ppm propane each) were

1 24
supplied by the state in question. Analysis revealed that the propane

concentrations in these two cylinders were, in fact, 2600 and 3200 ppm,

respect! vely

The above experience is probably not unique, and similar inconsistencies will undoubtedly continue to occur until all states adopt a vendor

certification program.

We are interested in continuing to interact with IM programs conducted

by states and to provide appropriate assistance as requested to aid in the

establishment of data quality assurance in state IM programs.

3 . Advances in Carbon Isotopic Ratio Measurements by Accelerator Mass

Spectrometry (15330)

L. A. Currie, G. A. Xlouda, J. M. Sullivan, and W. Ollison

Over the past few years, results of carbon and carbon isotope mea- surements on tropospheric gases and particles have given important information about sources of carooneous species in the atmosphere. The value of

carbon isotopic measurements is exemplified by the importance of 1 as a tracer for carbon frcm wood-burning which is increasing rapidly. These data

have added significance because of (a) the increased emissions of CO and

aerosols frcm wood combustion and Co) the recognition that "• 4 C is perhaps the

only reliable atmospheric tracer for wood-burning generated pollutants. This

year’s continued progress in trace carbon analytical chemistry focused on the

development and validation of techniques for measuring 1l4 C, 1 3c , and total

carbon in small samples of 50 to 1000 yg . This capability is crucial for

many atmospheric chemistry studies where concentrations of climatically

significant and toxic carbonaceous species limit the sample sizes to well

below the mg range.

Principal research has involved thermal separation of elemental

("graphitic") carbon and organic components from source and ambient particles, followed by characterization for 1 3c and ^C. In addition, Urban

Particulate SRM’s have been assayed for total carbon, carbon in the PAH

(Polycyclic Aromatic Hydrocarbons) fraction (cooperatively with

B. Diamondstone and S. Wise of Divisions 551 and 552, respectively) and ' “C

in each fraction. A dramatic difference in isotopic composition of the two

carbonaceous fractions was observed, reflecting a corresponding difference in

origin

The measurement of itself has been extended from our initial mass range (-5-10 mg carbon) to 100 yg carbon as a result of the use of Accelerator Mass Spectrometry (AMS). The AMS sample preparation at this level has

been evaluated, and the overall chemical blank has been determined to be

equivalent to 15 yg of contemporary carbon. Work completed in this area ~ reported at the 3rd international AMS Conference in April, 198^.

This past year we have applied the above techniques to char a — . r- atmospheric methane, as well as carbon particles from a vehicle tur.;.- . wooded areas, and wood-burning communities. A study completed in cm:*

with the Norwegian Institute for Air Research and the Central Ir.zi.' r Industrial Research in Norway gave interesting correlations aimrg t

•

• concentrations in particles, the meteorological conditions ar, i ert

125
inorganic and organic constituents. Measurements of 1 permitted the

determination of the winter-time contribution of wood-burning to the car- bonaceous particle burden in suburban Oslo. This was found to average about

70*.

Future work with environmental 1 will focus on extending the sensitivity down to a few yg-C using advanced sample preparation techniques in

which most or all of the chemical steps take place within a single system.

This will be linked with exploratory work with physicists at the University

of Pennsylvania tandem accelerator laboratory on the direct injection of CO 2 into the accelerator ion source. Additionally, we have underway studies of

carbon isotopes in atmospheric CO, CH 14 , and volatile organic carbon (the

latter in cooperation with a visiting scientist from the American Petroleum

Institute), to answer seme long standing questions concerning anthropogenic

vs natural origins of these species.

9. Development of a Definitive Treatment for the Calculation of Lower

Limits of Detection in Radionuclide Monitoring (15330)

L. A. Currie

A monograph has been prepared at the request of the Nuclear Regulatory

Commission (NRC) treating all major facets of the problem of estimating the

Lower Limit of Detection (LLD) in measurements of effluent and environmental

radioactivity. The monograph will serve as a manual for the guidance of

contractors, nuclear utilities and the NRC in the calculation of LLDs in

connection with Technical Specifications that are required for monitoring

effluents from operating nuclear reactors. Prior to the preparation of this

manual, the NRC had no single or unified source of guidance on this matter

which adequately represented their position.

At the outset of the two-year project which led to this manual, a comprehensive review was made of the literature on detection limits in

nuclear and analytical chemistry, spanning a period of 60 years with emphasis

on the last two decades. Following this, a number of site visits and

meetings took place with representati ves of NRC Headquarters and Regional

Offices, a trade organization (Atomic Industrial Forum), personnel from

nuclear power reactors, a standards laboratory, and commercial contracting

(radiochemical) laboratori es . These visits confirmed the need for a manual

since quite diverse and inconsistent approaches were in use.

The subject manual covers highlights of the current literature as well

as the nature of the regulatory requirement. Problems identified are treated

comprehensively in two sections: one presenting the basic principles of

detection and LLDs using the hypothesis testing framework; the other giving

explicit derivations and numerical illustrations for cases confronting the

nuclear industry. Topics covered include detection decisions vs detection

limits; the basic development in terms of the blank, its standard deviation

(variability), and calibration factors; the effect of deviations from

normality, as in low-level alpha counting; resolution algorithms and detection in multicomponent spectrometry and decay curve analysis; continuous

monitors such as noble gas count rate meters; multiple detection decisions;

reporting of "non-detected" results and the impact on averaging; and finally,

treatment of bounds for systematic error in the blank, in calibration

factors, and in spectroscopic models. Guidance on the design of nuclear

126
measurement processes to meet prescribed LLDs is also given, together with

comments on system optimization and asymptotic limits imposed by systematic

error and radioactive decay.

The comprehensi ve treatment provided by the manual should alleviate

many of the divergences in current practice, and it presents for the first

time, guidance for NRC licensees for the treatment of complex but realistic

problems involving LLDs in Y-ray spectroscopy, ultra-low-level counting, and

the inclusion of estimates of systematic error. A number of these topics

required new research in order to generate adequate and consistent solutions.

The results of these studies will be published separately in the scientific

literature

1 0 . A System for Traceable Calibration of Ozone Measurements Using the NSS

Primary Ozone Photometer (15330)

A. M. Bass

We are continuing to work with the Environmental Protection Agency

(EPA) on the development of their ozone monitoring network. In this connection we have provided to EPA several photometers based on the NBS primary

standard, and additional instruments are being planned.

The EPA has established ultraviolet absorption photometry as the

recommended method for the calibration of ozone-monitoring instruments. Based

on our experience in photometric measurements, we developed a highly sensitive and accurate instrument to serve as the NBS primary standard for ozone

assay. Similar photometers have been assembled at NBS for use by the EPA in

their program. These instruments will permit the EPA to maintain a uniform

ozone calibration system throughout their regional laboratories

During one past year two photometers were certified and delivered to

EPA, for a total of three instruments delivered. Construction was started on

two additional EPA instruments. These are scheduled for delivery by January

1, 1985. The EPA has performed in-house tests of these instruments and has

been completely satisfied with them. Planning is underway to establish a protocol for the regular maintenance and recertification of the network

instruments relative to the NBS primary standard.

1 1 . Research in Measurement Methodology Using Diode Laser Spectrometry and

the Determination of Spectroscopic and Kinetic Data for Reactive

Atmospheric Molecules (15330)

A. Fried and R. L. Sams

In our 1983 report, we presented results of a laboratory study

utilizing tunable diode laser absorption spectrometry to detect the import::'::

atmospheric gas HC1 at concentration levels below one ppb. This work, arc

the studies presented herein, are part of a long term program to develop an i characterize sensitive and selective laser-based spectroscopic technique.: re- measuring concentrations at, and below, the ppb level (ultra-trace level f such important atmospheric gases. Development of ultra-trace level st e : e : is an additional and parallel aspect of this program. In the prev; . report, a new calibration approach, using a known concentration

reactive reference gas, was briefly described. In the present n- ,

'

127
diode laser calibration aproach has been fully assessed for measurements of

HC1. A detailed computer modeling analysis was developed to account for

response differences between the reactive sample gas (HC1) and the nonreactive reference gas (CH n ) . The response factor ratios determined fran

this analysis were in excellent agreement with experimentally determined

values. This inter com pari son also revealed the optimum experimental regime

in which to carry out such calibrations. Because of some very important

advantages, the new calibration approach is being expanded to the calibration

of other important reactive molecules. Using this technique, the sample and

reference gases can be intercompared directly in the same cell, thus eliminating cell pathlength and repositioning errors as well as large signal

extrapolations indicative of more conventional optical calibration techniques. Perhaps the most important advantage is that tunable diode laser

measurements of reactive radicals can be performed in the field without the

need for a calibrated radical generation system. This has obvious

significance for diode laser measurements in the atmosphere.

In addition to the particular calibration approach employed, several

other factors dictate the overall accuracy with which gas concentrations can

be deduced fran quantitative diode laser measurements. Assessing these

factors for both absolute and relative measurements and improving accuracy

are on-going goals of our research program. Presently, the concentration of

most atmospheric species can only be determined with an accuracy in the

10-20? range by diode laser spectrometry using the absolute technique of

direct absorption. Our aim is to reduce this to below 5? for a number of

important molecules. To this end, progress has been achieved during the past

year on two fronts. First, we have improved our existing diode laser

facility by procuring a number of instrumental up-grades. One such purchase,

a confocal interf erometer , will now allow us to directly measure diode laser

linewidths concurrently with absorption measurements. This is important for

accurate concentration determinations in cases where the laser linewidth is a significant fraction of the molecular linewidth under study. Secondly, we have been actively collaborating with the Molecular Spectroscopy Division at

NBS to develop sophisticated canputer algorithms for line profiles. Such new

profiles, which include the effects of coll isional-narrowing , are important

to achieve accurate concentration determinations below the 10? level for

certain molecules.

During the past year, we have also initiated a tunable diode laser

research program to determine spectroscopic and kinetic data for the important atmospheric molecule HO2

. This work is at the beginning stage, and

results will be reported next year.

1 2. Development of an Improved Procedure to Calculate Characteristic X-ray

Fluorescence Corrections from an Electron Microprobe (15330)

R. L. Myklebust

In classical quantitative electron probe microanalysis, the matrix

correction factors have been separated into four different terms. These

terms are normally called the absorption, atomic number, fluorescence, and

continuum fluorescence corrections. Most computer programs employed in

quantitative analysis use only the first three correction factors. This is

satisfactory for most specimens since the effects of the fluorescence due to

the continuum are usually insignificant. We have examined the terms in the

128
characteristic fluorescence correction in an effort to update obsolete

parameters and to test the validity of some of the simplifications used in

the computational procedure. This effort is part of a long-term program

dedicated to the advancement of quantitative analysis techniques for the

electron microprobe.

For significant fluorescence to occur, a character! Stic x-ray line

(element b) in a specimen must be near, and on the high energy side of, the

x-ray absorption edge for the measured x-ray line of another element (element

a) in the specimen. X-ray fluorescence of element ’a* by x-rays of element

'b' will add x-ray photons from element ’a’ to those excited directly by the

incident electrons. If this effect is not taken into account, the calculated

concentration of element ’a’ in the specimen will be greater than the actual

concentration

Histori caily , a number of different expressions have been used to

calculate the fluorescence effect. We compared the two leading expressions

for characteristic fluorescence: (1) the full calculation of fluorescence

which is incorporated in the MBS matrix correction procedure, COR, and (2) a simplified version developed by Reed which is incorporated in the NBS matrix

correction procedure, FRAME. In addition, we compared results using different values for the fluorescence yields. The COR program used tabulated

values for fluorescence yields that were available prior to 1972. In the

program FRAME , an expression empirically fitted to the data in COR was used.

The results from the original programs were compared with results from both

programs modified with the more recently determined fluorescence yield values

compiled by Bambynek, et al. The fluorescence yields from Bambynek are much

higher than all of the previous values used in the FRAME and COR programs and

should generate larger fluorescence corrections. Experimental data exhibiting large corrections for character! sti c fluorescence were used to test the

different procedures. In the cases examined, the results produced by

Bambynek’ s expression show an improvement of 3 % relative or better over the

previous formulations in both COR and FRAME. This is a significant improvement since in optimum cases the error from quantitative analysis procedures

is 2 % relative or less. Reed’s expression for the fluorescence correction

still appears to be quite adequate for K-fluor escence . Further work is

required to test the correction for L-fluor escence and the fluorescence

yields for L-shells.

13- Development of an Automated Digital Image Aquisition System for

Analytical Electron Microscopy (15330)

R. L. Myklebust, E. B. Steel, and A. A. Bell

Efficient data collection from the analytical electron microscope

requires the development of digital image acquisition to replace existing

analog methods. A PDP 11/23 computer was interfaced to a JEOL 200CX analytical electron microscope for the purpose of producing digital images fr cm t.v. microscope. The scanning coils (bright field and dark field) of the elect r : microscope are controlled by digital-to-analog converters (DAC’s) , and in - output of the electron detectors on the microscopes are input to the c .t- —

via analog-to-digital converters (ADC's). The characteristic x-ray emissi

from a specimen may also be imaged through a multichannel analyz- r v '• multiple scalers. The scalers are in turn interfaced to the carp ui v: digital input module. A network link between the PDP 11/23 and a VAX i'
is used to transfer the images to the VAX. A Deanza IP8500 image analysis

system operating in conjunction with the VAX is used for image manipulation

and viewing.

The multichannel analyzer, its computer, the scalers, and the POP 11/23

system will all soon be replaced by a VAX 1 1 /730 computer and laboratory

automation system together with a modular multichannel analyzer. This new MCA is capable of collecting data from several different energy-dispersi ve detectors at the same time. The VAX 1 1 /730 will take over all of the

functions of the rest of the system and will have a direct memory access

(DMA) channel to the VAX 11/780 which should shorten the data transfer time

by about two orders of magnitude.

The image aquisition software controls the microscope so that either a scanning electron microscope (SEM) image, a scanning transmission electron

microscope (STEM) image, or electron energy loss spectrometer (EELS) image can be obtained. Each image consists of 51 2 x 512 up to 4096 x 4096 pixels

at magnifications of 20X to 800,000X and each pixel has a resolution of 8

bits (256 gray levels). For an electron image, the time required to collect

the image is about 2 minutes. Due to the small solid angle of collection for

the detector and the low x-ray yield of small particles, x-ray images require

a much longer aquisition time; therefore, a smaller number of pixels is

collected for these images. Up to 4 elements can be collected simultaneously

with the current system. In addition to the x-ray images, x-ray line scans

can be produced for up to 4 elements superimposed on the electron image of

the area in the microscope field. Sane early applications of the system have

included analyses of air particulates, asbestos, and several other mineral

particulates. The new digital imaging capabilities provide the means for

rapid intercomparison of images, combining of image and compositional

information, and compositional mapping.

1 4. Comparison of Boron-10 Depth Distributions as Determined by Spreading

Resistance, Secondary Ion Mass Spectrometry, and Neutron Depth

Profiling (18224)

D. S. Simons, B. R. Stallard, R. G. Downing, R. F. Fleming, and J. R. Ehrstein

Depth profiling of intentional dopants is an important measurement in

the semiconductor industry both for process and device modeling and for

process control. A comparison study of boron-10 implants into silicon as measured by spreading resistance profiling (SRP) , secondary ion mass spectrometry (SIMS), and neutron depth profiling (NDP) has been conducted. The boron

implantations were done at several fluences and energies into bare silicon

and through several thicknesses of thermally grown oxides. Both as-implanted

and thermally annealed wafers were studied. The purpose of this work was to

investigate the feasibility of developing a boron-in-silicon depth profiling

standard and to compare individual profiling methods.

The following conclusions emerged frcm this study. Spreading

resistance profiling exhibited a discrepancy in the low concentration tails

compared with either SIMS or NDP profiles. This discrepancy, which has been

observed previously, is attributable to the distinction between free-carrier

profiles as measured by SRP and atomic profiles as measured by SIMS and NDP.

While SIMS and NDP measure the same type of profile, the physical processes

130
that occur in the two analytical techniques are completely different, leading

to different analytical characteristics. The detection limit of boron by

SIMS where the signal is just detectable in a standard counting time was 1 0"

1 5 atcms/cc while that of NDP was 1

1 7 atcms/cc, and SIMS required a much

smaller sample area to achieve this limit of detection. The depth resolution

of SIMS was also found to be superior to NDP. On the other hand, NDP is

nondestructive while SIMS erodes a small crater in the sample, and NDP can provide a highly accurate measurement of the total implanted boron dose.

Unlike SIMS, NDP profiles of boron through Si02 -Si interfaces showed no detectable measurement artifacts in the profile at the interface. It is

clear from this study that the choice of proper profiling technique for boron

depends on the type of sample and the information desired, and the use of

more than one technique is often advantageous.

1 5. Development of Improved Elemental and Isotopic Measurements of

Micrometer Sizea Particles by Secondary Ion Mass Spectrometry (16224)

D. S. Simons

The National Bureau of Standards (NBS) organized, and participated in,

a blind round-robin analysis of micrometer-sized glass particles by secondary

ion mass spectrometry (SIMS). This study is part of an on-going effort of

the Microanalysis Research Group to evaluate and to improve the particle

analysis capaoilities of various mi or oanalytical instruments. The analyses

at NBS were carried out using the CAMECA IMS-3F Ion Microanalyzer

One phase of the study was the determination of the elemental composition of individual glass microchips from a single melt, with diameters

ranging from 10 to 25 micrometers. Special transfer optics were used to

maximize the ion collection efficiency from the small emission region. Ion

energy discrimination was used to minimize the spectral contribution of

molecular ions. Thirteen cations were identified in a survey mass scan. Tne

composition was determined by comparing the ion intensities of the elements

frcm the unknown chips with the intensities of the same elements from

standard glasses that were ground into chips of the sane size range. Measured

concentrations were as low as 300 ppm (atom ratio). The accuracy compared to

the batch value was within 5? relative for the major components, and within

10-20$ for the minor and trace components. One cation, cadmium, was net

detected owing to its low concentration and low ionization efficiency. These

results for the thirteen cations compare favorably in accuracy with electron

microprobe analysis for the major components. The low atomic number elements

lithium and boron and the trace components could not be detected with the

electron microprobe.

The second phase of the study involved the determination of the

isotopic composition of uranium in individual glass microchips containing ~ ’ (by weight) of uranium oxide. The isotopic abundance of U-2 35 in inunknowns varied frcm 0,2$ to 0.7$ with respect to the U-238. The transfer

optics were again set to maximize transmission efficiency and the spent.-'

meter was adjusted to obtain flat-topped peaks. The U-235/U-23S instrument

bias factor was determined frcm chips of the same elemental composit::r. f

• were known to have the natural isotopic composition of uranium,

accuracy of the isotopic ratio determination was better than 0.5^ r*_-i •.* and it was found to be limited only by counting statistics. This a about a factor of 5 better than the results obtained from an oiqe- g

131
of ion microprobes. In addition, for the first time it was demonstrated in

this study that a SIMS instrument could determine the isotopic abundances of

the minor isotopes U-23M and U-236 at levels below 10 ppm with respect to

U-238 in individual microparticles.

1 6. Evaluation of a Digital Image Analysis System for the Secondary Ion

Microanalyzer (15330)

D. S. Simons

In an effort to enhance our ion microscopy capabilities, a digital

image analysis system has been acquired for dedicated use with the CAMECA Ion

Microanalyzer . The system was developed by a subcontractor according to

design criteria and performance specifications defined by NBS. It consists of

(1) a 2-stage chevron microchannel plate-fluorescent screen image intensifier

that replaces the original single-stage assembly in the ion microanalyzer;

(2) a newvicon TV camera that views the ion image distribution displayed on

the fluorescent screen through a vacuum window; (3) a video digitizer and

frame storage unit that digitizes the analog video signal in real time ( 1 /30

s) and stores it in a 51 2 x 512 pixel array with 8 bits (256 levels) of

intensity resolution; and (4) a minicomputer and software package for image

manipulation, including contrast enhancement, multiple image registration

,

intensity line profiling, and image arithmetic such as background image

subtraction

Several major advantages of the digital image analysis system over real-time viewing of the ion image are the capability to sum multiple frames,

thereby improving the si gnal- to-noi se ratio, and the ability to view the

acquired image without further erosion of the sample. The visual detectability of low-level signals from localized areas was evaluated using the

images of 20 x 20 micrometer squares from an aluminum test sample. A series

of images was recorded under different conditions of ion flux, exposure time,

channel plate gain, and camera black level setting. The following conclusions were drawn: (1) the optimum channel plate gain for best signal- tcbackground contrast increases as the ion flux decreases; (2) a flux of MO

ions per second over a 20 x 20 micrometer area can be readily distinguished

frcm background in a one second exposure (a flux of 10 ions per second under

the same conditions is at the detection limit) and, (3) detectability of low

level signals is limited primarily by background pattern noise, and

secondarily by random channel plate noise.

Several examples of the value of the digital image analysis system have

already been demonstrated. A series of images of the spatial distributions

of different elements was collected from the same area of a nickel-based

alloy. The major elements nickel, chromium, and iron showed crystallographi

contrast in ion emission among different crystallite orientations which is a SIMS artifact that must be understood and compensated for if image i tensity

variations are to be converted to compositional variations. Numerical

division of one image by another on a pixel-by-pixel basis showed quickly and

conclusively that the magnitude of the contrast effect was not identical for

the three elements. Titanium and niobium were found to be localized in

inclusions. An overlay of the two images, each in a different color, showed

these elements to be mainly associated in the same inclusions, presumably a mixed Nb-Ti carbide.

132
17. Automated Object Identification From Digital Images (15330)

David S. Bright

Object identification by computer, despite the need for further

research, presents seme very real advantages in our microanalysis research

program. Because of this, we have embarked on a long term effort to develop

algorithms for recognition of simple two dimensional objects in specialised

types of images. Computer object identification is currently being employed

in three .areas: image matching, positron emission tomography (PET) scan

analysis, and electron diffraction pattern analysis.

In the area of image matching, images of spheres on a filter were taken

witn the electron microscope in the transmission mode and in the scattering

mode. The scattering mode image is distorted such that a simple superposition of the two images is not possible. An object sorting procedure has been

developed which can identify corresponding objects in both images. Once the

entire image has been mapped, the image distortion vector field can be

determined and ’ised to match pairs taken in the 3ame modes. As a result,

images from two different instruments can now be inter compared

Analysis of positron emission tomography scans of human brain is being

performed in collaboration with scientists at NIH. First, the image of the cross section of the brain is divided by the computer into several dozen

segments. Algorithms are being developed to identify these segments or group

these segments as meaningful objects. This process relies heavily on spatial

relationships of the segments as well as the properties of the individual

segments. Upon completion of this project, large homologous regions of the

brain will be identified without requiring intervention by highly trained

specialized personnel. This capability should significantly reduce the

analysis time as well as enhance the measurement precision.

In electron diffraction pattern analysis, an algorithm has been

developed for the analytical electron microscope. Diffraction patterns of

crystalline samples, taken with the analytical electron microscope, sometimes

consist of a regular array of spots from one crystal and many randomly spaced

spots. Considering the array of spots to be an object, an algorithm has been

developed to extract it and any others, one by one, leaving the randomly

spaced spots behind. To extract an object, the algorithm searches for a small group of regularly spaced spots, finds a set of basis vectors for that

group, and then finds the rest of the spots that can be located by means of

the basis vectors.

18. The Detection and Identification of Surface Organic Species by Laser

Ionization Mass Spectrometry (15330)

R. A. Fletcher

The analysis of adsorbed and chemisorbed organic species on mi r - structures, such as small particles and fibers, is difficult without

extracting the species of interest from the substrates. This homog-n

and possibly alters the sample. Laser desorption directly from the surf

of a particle or fiber is a unique and potentially valuable way of ar. , these adsorbates and relates to the objective of molecular ccrnposii: • mapping on small particles and surfaces. The laser microprobe mu,; am

133
(LAMMA 500) is a time-of-flight mass spectrometer that uses a ^ pm diameter

focused laser beam to desorb and ionize the sample. For organic analysis,

the important aspect of the instrument is the availability of a gentle

ionization process. This process utilizes low laser energy density conditions (< 1 J/cm2) on the sample surface to preserve the molecular structure

of many organic species. With increasing laser intensity, more molecular

fragmentation occurs which is useful for deriving structural information

about the organic species.

We have demonstrated that a monolayer of parani trobenzoi c acid (pNBA) can be desorbed and detected from the surface of silver island films and

silver surfaces. In this instance, the LAMMA was able to detect on the order

of 1 09 molecules of pNBA with minimal fragmentation to the molecular species.

In a second set of experiments, pNBA, succinic acid, and dioctyl phthalate

(DOP) have been desorbed frcm two dielectric surfaces - NBS glass spheres and

carbon particulates. These materials were placed on the substrate particle

surface by aerosolizing either carbon or glass spheres in a 0.001 mol/L

alcoholic solution of one of the above compounds. As the alcohol evaporates,

a thin coating of the desired organic species is left behind on the particles' surface. The particles are then caught on a grid and analyzed

directly by laser ionization mass spectrometry.

The mechanism for desorption and ionization from both types of

substrate materials (conductor and dielectric) is thought to be initiated by

rapid heating of the substrate which results from absorption of the incident

10 ns pulsed laser radiation. Analyses of asbestos fibers and fly ash

particles coated with organic compounds have been reported recently. Surface

analysis by laser ionization can be expanded to examine catalytic surfaces

and has been utilized to study polymer surfaces. In collaboration with Dr.

A. J. Fatiati (Division 552), polymer surfaces are currently being examined.

On these polymer surfaces a new immobilized copper chemistry is taking place

by means of coordinated metal complexes and ligand formation on polymer

beads. The metal coordination is thought to be only on the surface of the

polymer bead. Laser ionization mass spectra of the surface show organometal

ion fragments which supports the existence of this new metal structure.

Laser desorption/ ioni zation mass spectrometry offers a unique way of analyzing organic surface species on mi crostructur es such as small particles and

fibers. Monolayer coatings can be examined with -1 um spatial resolution.

The fundamental processes involved and the extent of applicability are under

investigation.

19. Comparison of Multichannel SIT Vidicon and Monochannel Photomultiplier

Detection in Micro-Raman Spectroscopy (15330)

E. S. Etz

As part of our long term micro-Raman research program, two types of

experimental Raman microprobes have been developed at NBS: (1) a scanning

spectrometer system with photomultiplier (PMT)/photon counting detection and

(2) a dispersive non-scanning system employing a prototype spectrograph

coupled to a multichannel SIT vidicon detector. In the study conducted this

past year, these two very different instruments were employed in the analysis

and characteri zation of particles. The performance figures of merit for both

instruments have been evaluated for several classes of microparticulate

material. The following instrumental comparisons were of principal interest
in these studies: (1) the relative detection sensitivities, (2) the spectral

signal-to-ncise ratios from weak scatterers, (3) the various tradeoffs

between spectral coverage and spectral resolution, and (4) the data acquisition times in cases where the samples were sensitive or unstable to laser

irradiation.

These factors were examined in experiments utilizing a classical double

monochromator with a coded PMT detector and a second microprobe employing a developmental triple spectrograph coupled to a cooled 500-channel SIT vidicon

with an ODtical multichannel analyzer. The two micro-Raman systems acquire,

process, and read out the spectral data differently as highlighted in this

comparison. Spectra of molecular solids — (inorganics, organics and polymers) have been acquired with both instruments using 51^.5 nm excitation. In

the multichannel system, this results in a complete spectrum that is readily

observable in real time (30 ms) vs scan times on the order of 5-15 min for

PMT detection with equivalent spectral coverage. In other measurements , we

have examined the weak Raman spectra of highly colored or opaque solids

(e.g., metal oxides, carbides) in which the effective laser power density

that can be employed is limited by sample modification due to heating. In a third class of materials, certain organic solids (e.g., nitre compounds),

time-dependent photcdecompcsition readily occurs. In general, spectra of

such molecules can be obtained only with multichannel detection employing

short (tyoically 1-3 minutes) 3ignal integration times. It is concluded from

these studies that soectrc graphic detection using the multichannel SIT

vidicon system is the preferred method for measuring the weak Raman signals

of laser-sensitive, labile scattering species. Future research in microRaman instrumentation will examine the relative merits of silicon photodiode

array vs. SIT vidicon detection.

20. The Certification of New Multielement Glass Standards for Analytical

Microprooes ( 1 5330)

R. 3. Marinenkc

As part of our program to produce and certify microanalyticai

standards, fifteen glasses have been issued as Standard Reference Materials

(SRM's) for use in microanalyticai techniques such as electron probe microanalysis ( EPMA) and secondary ion mass spectrometry (SIMS). These glasses

are unique since they provide matrix compositions not previously available ir. the more- commonly used standards. Because the materials are vitreous solids,

they are single phase and can be homogeneous on the micrometer scale,

addition, small amounts of other oxides, or dopants, have been added to the

melt without disturbing the microhomogeneity of the major constituents.

The fifteen glasses are divided into five different SRM’s (1871-’:'': , each containing three glasses and each represented by a different matrix. Tr- matrix glass in each SRM is composed only of the two or three major- cor. por. err. oxides while the other two glasses in the SRM have similar matrix c — : - - tions with the addition of small amounts (1-2 weight percent' of sever-:

dopants. The five different matrices are lead silicate, lead ger-r.v . barium-zinc silicate, aluminum-lithium borate, and aluminum-ms gr- . phosphate. The dopants include the oxides of zirconium, titanium , °'*i tantalum, iron, nickel, europium, uranium, thorium, and chromium.

135
Most of the major constituents in the glasses have been analyzed by wet

chemistry and EPMA. A few elements were analyzed by optical emission

spectrometry or neutron activation analysis. Certification values were determined from the weighted average of the results obtained from two or three methods of analysis. Weighting factors were based on the observed

variability of each analytical technique. A few of the major components are being issued with information values until additional analyses have been

completed. The dopant oxides were analyzed with EPMA and are issued as information values on the SRM certificates.

The major constituents in the glasses were tested for both micro- and

macrohomogeneity. Periodic integrator traces and random sampling techniques

were used. For each glass, intercomparisons between specimens as well as within specimens were evaluated using accepted statistical procedures. No

evidence of any practical inhomogeneity was found for any of the glasses.

These glass standards are expected to be of significant utility to the

microanalysis community. Similar standards have not been available in the

past. Not only are the matrix compositions unusual, but also few standards

with known low-concentration elements are presently available.

21. The Analysis of Natural Product SRM's by X-Ray Fluorescence (15330)

P. A. Pella and G. A. Sleater

During the past year, homogeneity studies were performed on various

natural products by XRF. Samples included in these studies were coal,

limestone, clay, and cement. These samples are being proposed as new Standard Reference Materials (SRM’s) or as replacements for present SRM's.

The ability to conduct analyses on a large number of similar samples with

high precision is an attribute that makes x-ray fluorescence (XRF) particularly amenable for homogeneity studies. Also important in this regard is the

fact that most analytical samples can be prepared for XRF study without

chemical pre-treatment and that the analytical data can be evaluated

statistically after measurement.

The analyses were performed using the Philips PW-1M00 automated

wavelength-dispersive spectrometer . The automated specimen changer attached

to this instrument permitted all the specimens to be analyzed in one continuous operation. In 1980, the computer program, H0M0TS, was developed (Paule,

Pella, and Tao) and was used to determine the elemental composition homogeneity. This was accomplished using a series of statistical variance tests on

the stored intensity data. Homogeneity tests were performed on SRM 679

(Brick Clay), SRM 88b (Dolomitic Limestone), and SRM's 1632a and 1 632b (Trace

Elements in Coal).

In addition, quantitative analyses were performed on most samples by

comparing the measured intensity data with those from standards. Standards

were either synthetic standards, made of selected elements in a benign matrix

such as fused glass, or comparison standards consisting of SRM specimens of

equivalent elemental composition and of similar matrix to the test -specimens

Suitable inter-element corrections were made in calculating concentrations

from the intensity data. Quantitative analyses were performed for SRM 1 8 80

("Black Cap" Cement), SRM 1881 ("White Cap" Cement), proposed SRM 679 (Brick

Clay), and SRM 88b (Dolomitic Limestone).

136
22. Improvements In the Algorithm for Calculating Fundamental Parameters

In Quantitative X-Ray Fluorescence Analysis (15330)

P. A. Pella and G. f. Tao

One of the long- term goals of the X-ray Fluorescence Group is to assess

and improve interelement correction procedures for quantitative x-ray

analysis for a wide variety of sample types. Previously we examined several

correction schemes to check for consistency in the results of chemical

analysis. These included selected semi-empirical as well as fundamental

parameter correction methods. Fundamental parameter methods are particularly

attractive in analytical situations where standards of the same type as the

analyte specimens are not available. It has been shown with the fundamental

parameter program NRLXRF, for example, that reasonable results on the order

of ±5% relative can be obtained in the analysis of major constituents using

only the pure elements for calibration. Further improvement necessitates

greater accuracy in first principle parameters such as output spectral

distributions of x-ray tubes and fluorescence yields. This past year we have

evaluated COLA, a comprehensive algorithm which uses correction coefficients

calculated from first principles proposed by LaChance. This canputer program

( NBSGSC ) was extensively modified at NBS to include several options for

calibration in addition to the NBS algorithm for calculating x-ray tube

soectral distributions for seven commonly used x-ray tubes at any desired

voltage. Samples chosen for evaluation included well-characterized alloys,

SRM cements in the form of pressed pellets, and selected minerals in the form

of fused disks. Both pure element as well as ’type' standards were used for

calibration, and the results agree usually within ±2% relative with the known

values for major constituents. Further improvements in the NBS algorithm for

spectral tube distribution calculations are anticipated by including a modified electron backscatter function. This will take into account that the

electron beam is usually at 45° and not at normal incidence to the tube

target material in most commercial x-ray tubes. We expect to evaluate these

modifications in our algorithm during the coming year.

A research paper describing our interccmparison work with COLA is

expected to be ready for publication before the end of 1984. The extended

version of the COLA program which we modified at NBS will be ready for

publication as an NBS technical publication in 1985.

137
C. Outputs and Interactions

(Gas and Particulate Science Division)

1. Publications

Bright, D. S. , "Stereo Presentation of Monte Carlo Electron Trajectory

Simulations," (accepted by J.( Microscopy) (198*0.

Cadoff, B. C. and Hodgeson, J. t "Passive Sampler for Ambient Levels of

Nitrogen Dioxide," An a1 y

f "Q**--€h«nt5try ,^7 2083-2085 ( 1983).

. SS, —

Gerlach, R. W., Currie, L. A., and Lewis, C. W. , "Review of the Quail Roost

II Receptor Model Simulation Exercise," in Proc. APCA Specialty Conference on Receptor Models Applied to Contemporary Air Pollution," SP—48

96 (1983).

Currie, L. A., Gerlach, R. W., Klouda , G. A., Ruegg, F. C., and Tompkins, G.

B. , "Miniature Signals and Miniature Counters: Accuracy Assurance via

Microprocessors and Multi parameter Control Techniques," Radiocarbon 25,

553 (1 983).

Voorhees, K. J. , Schulz, W. D., Currie, L. A., and Klouda, G. A., "An Investigation of the Insoluble Carbonaceous Material in Airborne

Particulates from Vehicular Emissions," (submitted to Environmental

Science and Technology (1983).

Ramdahl, T. , Schjoldager, J., Currie, L. A., Moller, M., Hanssen, J. E.

,

Klouda, G. A., and Alfheim, I., "Ambient Impact of Residential Wood

Combustion in Elverum, Norway," Sci. Total Environ. 36 , 81-90 (1984).

Currie, L. A., Gerlach, R. W., Lewis, C. W., Balfour, W. D., Cooper, J. A.,

and Dattner, S. L. , "Interlaboratory Comparison of Source Apportionment

Procedures: Results for Simulated Data Sets," Atmospheric Environment

^8, 151 7 ( 1984) .

Currie, L. A., "Chemometri cs and Analytical Chemistry: Societal Issues,

Structure of the Measurement Process, Detection, and Validation,"

Chemometrics : Mathematics and Statistics , B. R. Kowalski, Ed., (Reidel

Publishing Co . ) (1984).

Currie, L. A., Klouda, G. A., and Voorhees K. J. , "Atmospheric Carbon: The

Importance of Accelerator Mass Spectrometry ," Nuclear Instrum. Methods

( 1 984) , in press .

Currie, L. A., "The Many Dimensions of Detection in Chemical Analysis,"

Chemometrics in Pesticide/Environmental Residue Analytical Determina- tions , ACS Sympos. Series (1984).

Currie, L. A., Klouda, G. A., Elmore, D., and Gove, H. E. , "Radiocarbon

Dating of Microgram Samples: Accelerator Mass Spectrometry and Electromagnetic Isotope Separation," submitted to Nature (1984).

Currie, L. A., "The Lower Limit of Detection: Radiological Effluent and

Environmental Measurements , " NRC ( 1984).
Elkins, J. W . , Kagann, R. H. , and Sams, R. L. , "Infrared Band Strengths for

Methyl Chloride in the Regions of Atmospheric Interest," Journal of

Molecular Spectroscopy 105 , 480-490 (1984).

Marinenko, G. , Koch, W. F., and Etz, E. S. , "High Precision Cculcmetric

Titration of Uranium," J. Research Natl. Bur. Stds. 88 , 117 (1983).

Etz, E. S., Rudd, D. A., and Sawyer, G. W. , "Analytical Characterization of

Seme High Explosives by Raman Micrcprobe Spectroscopy," submitted to

Applied Spectroscopy

Fletcher, R. A., "A Review of Personal/Portable Airborne-Particulate

Monitors," J. Air Pollution Control Association (in press).

Fletcher, R. A. and Fatiadi, A. J., "Structure of Metal-Coordinated

Polymers. Laser Desorption of Poly( 4-vinyipyri dine ) and ?oly( 4-vinyipyridine)-Metal Complexes" Microbeam Analysis , San Francisco Press,

Inc. (1984).

Fletcher, R. A. and Fatiadi, A. J. , "Laser Ionization Mass Spectrometry of

Poly(4-vinylpyridine) ," Anal. Chem. (in review).

"letcher, R. A., Final Report to EPA regarding Personal Environmental

Monitors (PEM) '''’984'

Fried, A., Sams, R., and Berg, W., "Detection of HC1 at the Sub-Parts-PerBillion Level Using Tunable Diode Laser Absorption," Proceedings of the

Society of Photo-Optical Instrumentation Engineers: Tunable Dioce

Laser Development and Spectrosocpy Applications, 438 (1983).

Fried, A., Sams, R. , and Berg, W. , "Application of Tunable Diode Laser

Absorption for Trace Stratospheric Measurements of HC1: Laboratory

Results, Applied Optics 23 (11), 1867 (1984).

Pine, A. S. , Fried, A., and Elkins, J. W., "Spectral Intensities in the

Fundamental Bands of HF and HC1," accepted for publication in the

Journal of Molecular Spectroscopy.

Klouda, G. A., Currie, L. A., Donahue, D. J. , Jull, A. J. T. , and Zabel

,

T. H., "Accelerator Mass Spectrometry Sample Preparation: Methods for

1 in 50-1000 Microgram Samples," Nuclear Instrum. Meth. (1984), in

press

Marinenko, R. 3. and Blackburn, D. H., "Glasses for Microanalysis: New NES

(USA) Standard Reference Materials," J. de Physique Vol . 45 ( 198 a).

Kulle, T. J., Milman, J. H., Sauder, L. R. , Kerr, H. D., Farrell, B. P., ant

Miller, W. R. , "Pulmonary Function Adaptation to Ozone in Subjects wit r. Chronic Bronchitis," Environmental Research 34 , 55-63 (1984).

Myklebust, R. L. , "An Evaluation of X-ray Loss Due to Electron Backseat:. • r

'

, " J. de Physique, supplement 2, 45, C2-41-C2-42 (1984).

139
Myklebust, R. L. and Marinenko, R. B. , "A Re-examination of the Characteristic Fluorescence Correction," Microheam Anaiysis-1 984, Bethlehem, PA

(1984).

Myklebust, R. L. and Thorne, B. B. , "A Fortran Version of the Quantitative Energy-Dispersive Electron Beam X-ray Analysis Program FRAME C,"

NBS Tech. Note 1200 (1984).

Butrymowicz, D. B. , Piccone, T. J. , Manning, J. R., and Newbury, D. E. , "Color Metallography of Diffusion-Induced Grain Boundary Migration in

Cu-Zn and Cu-As Alleys," Metallography 1

, 349-36 (1983).

Taylor, H. F. W. and Newbury, D. E. , "Calcium Hydroxide Distribution and

Calcium Silicate Hydrate composition in Tricalcium Silicate and betaDicalcium Silicate Pastes," Cement and Concrete Research 14, 93 — 9 8

(1 984).

Peacor , D. R., Dunn, P. J. , Roberts, W. L. , Campbell, T. J. , and Newbury, D.

E. , "Fransolite, A New Calcium Beryllium Phosphate from the Tip Top

Pegamatite, Custer, South Dakota," Bulletin Mineralogy 106 (1983).

Williams, D. B. and Newbury, D. E. , "Recent Advances in the Electron

Microscopy of Materials," Advances in Electronics and Electron Physics , ed. Peter Hawkes (Academic Press, London, 1984) 161-288.

Butrymowicz, D. B. , Cahn , J. W., Manning, J. R., Newbury, D. E. , and Piccone,

T. J., "Diffusion-Induced Grain-Boundary Migration," Character on Grain Boundaries , ed. M. F. Yan and A. H. Heuer , Advances in Ceramics

6, (American Ceramics Society, Columbus, Ohio) 202-21 2 (1983).

Newbury, D. E. and Simons, D., "The Role of Standards in Secondary Ion Mass

Spectrometry," Secondary Ion Mass Spectrometry (SIMS IV) ed. A. Benninghoven , J. Okano, R. Shimizu, and H. W. Werner ( Springer-Verlag

,

Berlin, 1984) 101-106.

Newbury, D. E. , "Microbeam Analysis of Samples of Unusual Shape," J. de

Physique , supplement 2, vol. 45 C2-775-C2-780 (1984).

Newbury, D. E. , Myklebust, R. L. , and Steel, E. B. , "Use of a Monte Carlo

Electron Trajectory Simulation for Quantitative Analysis of Thick Films

in the Electron-Probe Microanalyzer," Microbeam Analysis-1984 (San

Francisco Press, 1984) 198-200.

Newbury, D. E. and Myklebust, R. L. , "Monte Carlo Electron Trajectory

Calculations of Electron Interactions in Samples with Special

Geometries," in Electron Beam Interactions with Solids, D. F. Kyser, D.

E. Newbury, H. Niedrig, and R. Shimizu (eds.), SEM Inc., AMF O'Hare, IL

60666, p. 1 53-1 63 ( 1984) .

Pella, P. A., Feng, L. , and Small, J. A., "A Comprehensive Algorith for the

Calculation of X-Ray Tube Output spectral Distributions for Quantitative X-Ray Fluorescence Analysis," submitted to Journal of X-Ray

Spectrometry
Rhoderick, G. C., Cuthell, W. F. , and Zielinski, W. L., Jr., "A Gravimetric

Technique for the Preparation of Accurate Trace Organic Gas Standards,"

Proceedings APCA Specialty Conference on Quality Assurance in Air

Pollution Measurements , Boulder, CO, October 1 98-4 , in press.

Lutz, G. J., Rock, H. L., and Lindstrom, R. M., "Determination of 1-129 at

Natural Levels by Thermal Neutron Activation Analysis," J. Trace and

Microprobe Tech . 2, No. 1, pp. 33~53 0984).

Rcok, H. !., "The Role of NAA in Trace Analysis," submitted to J. T^ace and

Microprobe Tech. (1984).

Sieber, J. R. and Pella, ?. A., "Improved Cobalt Determination in Steel by

X-Ray Spectrometry , " 11th Meeting of the Federation of Analytical

Chemistry and Spectroscopy Societies (FACSS), Phil. PA (1984).

Steel, E. 8., Simons, D. 3., Small, J. A., and Newbury, D. E., "Analysis of

Submicrcmeter Particles by Sequential Analytical Electron Microscopy

and Laser Micrcprobe Mass Analysis," Microbeam Analysis-1984 27-30.

Steel, E. 3., Small, and J. A., "Analytical Errors in Asbestos Analysis by

Analytical Electron Microscopy," NBS Special Publication 619: Asbestos

Standards: Materials and Analytical Methods. US Govt. Printing

Office, Washington, DC p. 162 (1984).

Steel, E. B., Simons, D. S., Small. J. A., and Newbury, D. E., "Analysis of

Submicrometer Particles Using Sequential AEM and LAMMA , " Microbeam

Analysis (1984).

Steel, E. B. ana Small, J. A., "Accuracy of Analytical Electron Microscopy

for the Analysis of Asbestos in Ambient Environments , " submitted to

Analytical Chemistry .

Steel, E. B. and Small, J. A., "Analytical Methods: Light and Electron

Microscopy," Proceedings of Workshop on the Monitoring and Evaluation

of Airborne Asbetos Levels Following an Abatement Program (1984).

2 . Talks

Bass, A. M., "Status Report on Ultraviolet Ozone Cross Sections," NASA, GSFC,

(11/83), University of Reims, France (5/84).

Bass, A. M. , "Calibration of Ozone Monitors," Harvard University, ( 6 / 3 - .

Bright, D. S., "Computers and Learning," George Washington University, Washington, DC (3/1/84.)

Bright, D. S., "Image Analysis with LISP Using Spatial Relationships,"

Barbara Research Corp., Goleta, CA (7/13/84).

Bright, D. S., "Computer Matching Two Different Images of the Sane ?:m*

Fields," Microbeam Analysis Society, Bethlehem, PA (7/1 8/3- .

Bright, D. S., "Segmentation of PET Brain Images into Anatomically

Regions," IEEE Computer Society, Arlington, VA (7/24/6:.).

141
Bright, D. S. , "Segmentation of PET Brain Images into Anatomically Meaningful

Regions, Progress Summary," NIH National Cancer Inst., Bethesda, MD

(8/8/84).

Currie, L. A., "Seme Open Problems in Chemometri cs : Detection, Regulation,

and Multivariate Data,” NBS (10/19/83). (Invited)

Currie, L. A., "Atmospheric Carbon: The Importance of AMS," 3rd

International Symposium on Accelerator Mass Spectrometry, Switzerland,

(4/12/84). (Invited)

Currie, L. A., "The Use of Carbon Isotopes in Source Apportionment of Organic

Species in the Atmosphere," Workshop on Genotoxic Air Pollutants,

USEPA, Rougemont, NC (4/26/84). (Invited)

Currie, L. A., "Introductory Remarks and Session Chairman for Organic Dating," 24th International Archaeometry Symposium, Smithsonian Inst.,

Washington, DC (5/18/84). (Invited)

Currie, L. A., "Detection Limit Estimation from an Empirical Calibration Data

Matrix," NBS (7/24/84). (Invited)

Currie, L. A., "I^c as a Tracer for Carbonaceous Aerosols: Measurement Techniques, Standards and Applications," 1st International Aerosol Conference, Minneapolis, MN (9/17/84). (Invited)

Elkins, J. W. , "Recent Results on Band Strength Measurements for a Number of

Gases," Nicolet FTIR User's Meeting, Nicolet Instruments, Madison, WI

(10/5/83)

Etz, E. S. , "Raman Microprobes and Their Use in Chemical Microanalysis,

University of California, Davis CA (1/19/84). (Invited)

Etz, E. S. , "The Role of Microprobe Spectroscopy in Interdisciplinary Materials Characterization ," McClellan Central Lab., McClellan AFB, CA

(2/17/84) .

Etz, E. S. , "Characterization of Airborne Particulates by Raman Micrprobe

Analysis," Atmospheric Sciences Division, Lawrence Berkeley Lab.,

Berkeley, CA (2/24/84). (Invited)

Etz, E. S. , "Analytical Characterization of Explosives Particles with a Multichannel Raman Microprobe," 19th Annual Meeting of the MAS,

Bethlehem, PA (7/17/84).

Etz, E. S. , "Instrumentation and Techniques of Raman Microprobe Spectroscopy

in Materials Analysis," Owens/Corning Fiberglas, Granville, OH

(9/13/84). (Invited)

Fletcher, R. A., "Structure of Metal-Coordinated Polymers. Laser Desorption

of Poly ( 4-vinylpyridene and Poly ( 4-vinylpyridene ) Metal Complexes,"

MAS, Bethlehem, PA (7/9/84).
Fletcher, R. A., "Fine Particulate Monitoring with Portable Personnel

Monitors," ASTM , Johnson, VT (7/1 2/8-4 ) •

Fried, A., "Detection of HC1 at the Sub-Parts-Per-Billion Level Using Tunable

Diode Laser Absorption," Joint Army-Navy-NASA-Air Force Safety and

Enironmental Protection Subcommittee Workshop on Toxic Vapor Teen., San

Diego, CA (10/13/83). (Invited)

Fried, A., "Photothermal Spectroscopy," presented at the Society for Applied

Spectroscopy , (2/21/84). (Invited)

Fried, A., "Laser Specoroscopi c Techniques for in situ Detection of Trace

Atmospheric Gases," Physical Sciences Lab., New Mexico State University

( 4/6/84) . ( Invited)

Klouda, G., "AMS Sample Preparation: Methods for 1 in 50-1 000 Microgram

Samples," 3rd International Symposium on Accelerator Mas3 Spectrometry,

Switzerland (4/1 2/84) .

Marinenko, R. 3., "Use and Abuse of Quantitative Wavelength Dispersive X-ray

Microanalysis," 19th Annual MAS Meeting, Bethlehem, PA ( 7 / 19 / 84 ).

Mitchell, G. D., "Performance Characteristics of Organic and Inorganic Gas

Permeation Tubes as an Standard Reference Materials," National Organization of Black Chemists and Chemical Engineers, Houston, TX

(4/26/84) .

Mitchell, G. D., "A Theoretical Approach to the Understanding of Permeation

Tubes and Other Control Release Devices," Hampton Institute, Hampton,

VA (2/15/84).

Mvklebust, R. L. , "A Re-Examination of the Characteristic Fluorescence Correction," MAS, Bethlehem, PA (7/19/84).

Newbury, D. E. , "Scanning Electron Microscopy and Microanalysis", NBS Staff

Research Series sponsored by the Research Advisory Committee,

(12/15/84).

Newbury, D. E. , "Applications of Scanning Electron Microscopy-Discussion,"

American Society for Metals, Seminar on "Modern Techniques of

Microstruct ural and Surface Analysis," NBS (4/2/84).

Newbury, D. E. , "Secondary Ion Mass Spectrometry," American Society for

Metals, Seminar on "Modern Techniques of Microstruct ural and SurfacAnalysis," NBS, (4/3/84)

Newbury, D. E. , "Microscopy and Microanalysis of Solid Specimens," MI CR C •• Conference sponsored by the Royal Microscopical Society, Lon tv.

(7/1 1 /84) .

Newbury, D. E. , "Use of a Monte Carlo Electron Trajectory Simulatirr. f r Quantitative Analysis of Thick Films in the Electron Prob-‘ V. analyzer," MAS, Bethlehem, PA (7/19/84).

143
Newbury, D. E. , "Specimen Preparation for Electron Beam Analysis," MAS,

Bethlehem, PA (7/19/84).

Newbury, D. E. , "Observations on the Calculation of k^ Factors for

Analytical Electron Microscopy," MAS, Bethlehem, PA (7/19/84).

Pella, P. A., "Preparation of Reference Materials for X-Ray Fluorescence

Analysis", ASTM Committee E02 on Emission Spectroscopy, Bal Harbour, FL

(10/19/83) . (Invited)

Pella, P. A., "Analysis with Fundamental Parameters Using a NBS Algorithm for

Calculation of X-Ra Tube Spectral Distribution," 33rd Denver X-Ray

Conference, Denver, CO (8/1/84).

Rook, H. L. , "Traceability Protocols for Commercially Certified Gas Reference

Materials," NBS Director’s Workshop on Measurement Service

Effectiveness (12/7/84).

Simons, D. S. , "Microanalysis Research at NBS," ACS, University of Delaware,

Newark, DE (10/19/83) .

Simons, D. S. , "Applications of Laser Microprobe Mass Spectrometry in

Biological Research," NIH, Research Triangle Park, NC (2/24/84)

Small, J. A., "The Analysis of Individual Atmospheric Particles Using

Advanced Microprobe Techniques," 1 984 Johnson Conference, Vermont

(7/12/84) .

Small, J. A., "Sample Preparation Techniques for Particles," MAS, Bethlehem,

PA (7/17/84) .

Small, J. A., "X-ray Bremsstrahlung Emission from Solid Targets: An

Empirical Model," MAS, Bethlehem, PA (7/20/84).

Steel, E. B. , "Ion Sputtered Thin Glass Film Standards for Analytical

Electron Microscopy," 4th Analytical Electron Microscope Workshop,

Bethlehem, PA (7/20/84).

Steel, E. B. , "Analysis of Submi crometer Particles Using Sequential AEM and

LAMMA," MAS, Bethlehem, PA (7/16/84).

Zielinski, W. L. , Jr., Gerald A. Sleater, and George Ulma, "Evaluation of

Degree of Sorption in Collection of Trace Organic Vapors on Sorbents,"

35th Pittsburgh Confernce on Analytical Chemistry and Applied

Spectroscopy, Atlantic City, NJ (3/84).

Zielinski, W. L. , Jr., William F. Cuthrell, and George C. Rhoderick, "Gas

Chromatographi c Analysis and Certification of Gravimetrically Prepared

Gaseous Toxic Organic Standards in the Low ppm and ppb Range," 20th

International Symposium on Advances in Chromatography , New York City,

NY (4/84)

( Invi ted)
lcr~ Lz~.ee Assienments

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Chairman

,

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22, 23 Sampling an d Analysis of Arc lent Atmos phe:

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Associate Member, 11*? A. C Commission on .Anal vs i cal '" M.eooer, NASA Scientific Advisory Panel ionAgo^ £ ,

an: Analysis

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Edgar Etz

Member, ASTM D-22 Methods Vw-- ^ LTr.ir.^ anc Analysis c

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Member

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I3C/TC 158 WG-1 Terminology

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Raymond M cK en zi

W ojr be r , ASTV D-22 Sam

M em be” , i_3 T m D-22. 03 ! M em be r , ASTV D-22. 05

Member , ASTM D-22. 07 : V Pfp 50 r*»

^ ASTM 1-29 Par

t MyklebtLS t Vor Kp r Mi or cbearn Ana

Member

,

ASTM E-2 Emis

V or 5^0 ri ASTM E-2.0H S

Newbury

Presi derit, Mi or cbe am . Member

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.ASTM E~ ~2 Sur

V y50r*<

^ Jour nal of w i Member

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s ”2*' i r* ~ r ”«' * •*-** 5 > *- - -

ng ar.o Analysis of Atsospr.e-es

Monitoring Instrumentation

al ibr at ion

jscopy , Editorial : ev;e-

'i al Review Bo ar d
Member, J. Trace and Microprobe Techniques, Editorial Review Board

Member, Sigma Xi

Member, Journal of Electron Microscopy Technique, Editorial Review

Board

Peter Pella

Member, ASTM E-2 Emission Spectroscopy

Member, ASTM E-2. 02 Statistics, Calibration and Standardization

Gerald SI eater

Member, ASTM D-22 Sampling and Analysis of Atmospheres

Member, ASTM D-22. 06 Source Sampling

Member, ASTM D-22. 07 Precision and Accuracy of Methods

Walter Zielinski

Member, Interagency Committee on C0 2 and Climate

Member, Interagency Committee for Stratospheri c Ozone Protection

Member, Interagency Committee for Indoor Air Quality

Member, ASTM D-22 Sampling and Analysis of Atmospheres

Chairman, Center for Analytical Chemistry Colloquium Committee

4. Other

a. Seminars

December 19, 1983 Dr. William Herget

Nicolet Analytical Instruments

"Gas Analysis with Fourier Transform Infrared Spectroscopy"

(Division Sponsor: J. Elkins)

March 30, 1 984 A. Dixon, Thor Instruments

"Improvements in the Quality and

Spatial Resolution of Small Area

X-ray Photoelectron Spectroscopy"

(Divison Sponsor: D. Newbury)

April 9, 1984 J. Michael, Lehigh University

"Application of Analytical Electron Microscopy to Grain Boundary

Segregation in Copper-Bismuth

Alloys" (Divison Sponsor:

D. Newbury)

May 15, 1984 Dr. Wilfried Vandercorst

Bell Northern Research, Canada

"Profiling with Quadrapole and

Magnetic Sector SIMS Instrumentation" (Divison Sponsor: D. Newbury)

146
b. Standard Reference Materials

X-Ray Fluorescence

1 1 72 NI-CR-MO Steel

C 1 1 73 Cast Steel 3

Cl 1 73a Cast Steel 3 1615 Vanadium and Nickel in Residual Fuel Oil

1832 Cements

1880 Portland Cement, Black

1881 Portland Cement, White

2633 Sulfur in Coals

Gas Metrology

1625 sc2 Perme at;io n i'ube

1 65 8a Met han e in Ai r

1 659a Methane in Air

1 660a Methane/Propane in Air

1 661 SO? in Nitr’Ogen

1 662 so; in Nitrogen

1 565 On q pan e in Air 1665b Propane in Ai r»

1 666 Propane in Ai r

1 666b Propane in Air

1 667 Propane in Air

1 667b Propane in Air

1668 Pro pane in Ai p

1 668b Propane in Ai p

1 669 Pr* 0 pane in Ai r

1 669b Propane in Ai r 1677 CO in N 2

1 678 CO in N 2

1679 CO in N 2

1 680 CC in N 2

1681 CO in N 2

1 683 NO in N 2

1 684 NO in N 2

1 685 Nitric Oxide in Nitrogen NO

1686 Nit ric Oxicle in Nitrogen NO

1687 Nitric Oxide in Nitrogen NO

1 693 SO 2 in N 2

1 693a S02 in N 2

1 694a S02 in N 2

1809 Tetrachloroethyl. ene in N;? 261 2 CO in Air

261 3 CO in Air

261 3a CO in Air

261 4 CO in Air

261 4a CO in Air

2620 CO 2 in N 2 2621 C0 2 in N 2 2622 CO 2 in N2

1 147
2625 C02 in N 2

2626 C0 2 in N 2

2627 NO in N 2

2628 NO in N 2

2629 NO in N 2

2637 CO in N 2

2638 CO in N 2

Atmospheric Chemistry

1648 1 ^C in Total C and Organic Fractions

1649 1 ^C in Total C and Organic Fractions

148
U.S. DEPT. OP COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 84-2979

2. Performing Organ. Report No, 3. Publication Date

December 1984

4. TITLE AND SUBTITLE

Technical Activities, 1984, Center for Analytical Chemistry

5. AUTHOR(S)

R. A. Velapoldi, H. S. Hertz, J. K. Taylor

G. PERFORMING ORGANIZATION (If joint or other than MBS. see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

I. Type of Report 8, Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State. ZIP)

Same as above.

10.

SUPPLEMENTARY NOTES

[~ "| Document describes a computer program; SF-I8S, FlPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a si gmficsnt

bi bliography or literature survey, mention it here)

This report summarizes the technical activities of the Center for

Analytical Chemistry at the National Bureau of Standards. It emphasizes

activities over the Fiscal Year 1984 in the Inorganic Analytical Research

Division, the Organic Analytical Research Division, and the Gas and

Particulate Science Division. In addition, it describes certain special

activities in the Center including quality assurance and voluntary

standardization coordination.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize on ly proper names; and separate key wore; tv sem .

:

analytical chemistry; analytical services; gas and particulate science; inorcanic

analytical chemistry; organic analytical chemistry; quality assurance; voluntar. .st : a.j

13. AVAILABILITY 14. NO. OF

PRINTED PAGES

| y | Unlimited For Official Distribution. Do Not Release to NTIS 156

1 j Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. IS. Price

|XJ Order From National Technical Information Service (NTIS), Springfield, VA. 22161 Si 6 .00

f\ UlCOuu.QC