//£ Of'/7J3 /f

EPA- I AG -D3-E684

NBS/EPA ENERGY ENVIRONMENT PROJECT

SEMI-ANNUAL REPORT

TO

ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF ENERGY, MINERALS, AND INDUSTRY

WASHINGTON, D. C. 20460

FEBRUARY 19 7 9

£ Juris* •

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

WASHINGTON, D. C. 20254
FOREWORD

The role of the National Bureau of Standards (N'BS) in the

Interagency Energy/Environment R$D program, coordinated by

the Office of Research and Development, U. S. Environmental

Protection Agency, is to provide those services necessary to

assure data quality in measurements being made by a wide

variety of Federal, state, local, and private industry participants in the entire program. The work at NBS is under

the direction of the Office of Environmental Measurements and

is conducted in the Center for Analytical Chemistry and the

Center for Radiation Research. NBS activities are in the

Characterization, Measurement, and Monitoring Program category

and addresss data quality assurance needs in the areas of air

and water measurement methods, standards, and instrumentation.

NBS outputs in support of this program consist of the development and descript ion ' of new or improved methods of measurement,

studies of the feasibility of production of Standard Reference.

Materials for the calibration of both field and laboratory

instruments, and the development of data on the physical and

chemical properties of materials of environmental importance

in energy production. This report is one of a series issued

every six months by NBS to provide information to the interagency

Energy/Environment community on the status of methods, standards

and data projects at NBS. Detailed project information is also

provided in the Interagency Energy/Environment Research and

Development Series.

C. C. Gravatt

Chief, Office of Environmental Measurements

National Bureau of Standards
INTRODUCTION AND SUMMARY

This report describes work performed by' the National Bureau of

Standards (NBS) during the period, July 19 ”3 to January 1979,

under the Interagency Agreement (EPA/ IAG-D8 -E684) between the

U. S. Environmental Protection Agency and NBS. This agreement

covers the development of standards, methods, data, and instrumentation for the measurement of pollutants associated with energy

production and use. The categories for this reporting period are

represented by seven subagreement areas and are reported as

follows:

80 BCKa — Energv Related Pollutant Measurement and Instrumentation

Development

Under the task Ener gy-Related Water Pollutant Analysis Instrumentation work done with the cerium oxidative detection system for

detection of phenols in the effluent of a liquid chromatograph was

found to have a detection limit in the order of 10 ng phenol.

A new type of probe was also constructed for LC-MS interface, and

• • use of iso-octane solvent was found to provide better results.

Studies done in the area of particulate analysis using secondary

ion mass spectra from organic layers was applied to metallic

particles

.

In the laser-enhanced ionization (LEI) area, work focused

primarily on improved refinements in the detection limit table,

completion of a workable theoretical model to explain and predict

experimental sensitivities and initial real sample measurements.

LEI has been demonstrated for 18 elements in water at the sub -ppm

leve 1

.

i i i
80 BCKb — Energy Related Water Pollutant Analysis Instrumentation

A pr eject has been i nit iat ed this period on the de

Spec if ic Immunoassay s for Di.nit rop heno 1

in Wat er

pro t e ins were produc ed to be used in the assay of

anti seraAll antis era we re assay ed for specif ici

doub le ga s diffusion and p as sive h emagglutinati on

Unde r generation of Enhanc ed CARS Spectr a of Organ

Capi 11 ary Waveguides , a new approach to analys

s 0

comp ounds in liquid phase by Raman Spectroscopy ha

This technique can b e adap te d to a f low- through ge

to HPLC

,

to improve the de te ct ion sensit ivity o f s

velopment of

DNA- conj ugate

purchased

ty and titre by

ic Liquids in

f organic

s been develope

ometry coupled

uch systems.

d

d.

SO BCLa Energy Related Pollutants and Effects Monitoring and

Associated Methods and Techniques Development

Under the task Development of SRMs for Stationary Sources Associated with Energy Production, results of analyses of two concentrations of NO ? in air suggests a degree of stability suitable for

a possible SRM. Under Development of SRMs for the Monitoring of

Ambient Air Impacted by Emissions Resulting from Energy Production,

study of feasibility of a low concentration sulfur dioxide - in - air

compressed gas SRM has been completed. Due to instability of

cylinders these gas mixtures would not serve as satisfactory SRMs,

but possibly as secondary standards. Results obtained thus far

show a slow decline in the concentration of nitric oxide, which

would make mixtures in the concentration range of 1500 ppm unsuitable as SRMs. High concentrations of hydrocarbons were found in

samples of carbon monoxide- in- air in cylinders lined with ceresin

wax. The Computer-Operated Gas Analysis System (COGAS) has been

modified and programmed to automatically analyze gas SRMs using

gas chromatographic and other discontinuous analyzers. This system

is now being used routinely for certification of all gas SRMs.

IV
Untie' i* Develop Methods for Dispersal of Particulates on Filter

Media and Methods for Determining and Controlling the Composition

and Morphology of such Dispersed Particulates, work was concentrated on focused ion-beam sputtering. The larger machine used

produced films whose composition was closer to the bulk target

composition for Ca, Zn, and Pb. Results thus far indicate that

ion acceleration voltage and ion-beam current determine the rate

at which the sputtered secondary atoms leave the surface of the

target, with no significant change in the film composition. Also,

the addition of oxygen to the sputtering atmosphere appears to

increase the content of ZnO and PbO in the films and decrease the

amount of trapped argon in the films.

In work with the Particle Doppler Shift Spectrometer, progress has

been made in the optical configuration, chamber design and in the

data collection method. Also, for the first time, experimental

data reproducibility matches the calculated Mie Scattering Curve

features over a broad range of sizes.

The Ion Chromatograph instrument is now fully operational and has

been used to analyze diverse sample types. In addition to sulfate

and nitrate on glass fiber filters, other sample types analyzed

were lyophilized oyster tissue, mechanical packing products,

penetrant inspection materials, and waste oil.

A mu 1 1

i - clement radioanaly tical procedure for the simultaneous

determination of As, Cr, Se, Sb , Cd, and Cu was developed and

applied to a new Fly Ash SRM (1653a) and a new Sub -bituminous

teal SRM (1635).

t : r 1 i ;

i na ry analysis of a proposed Oil Shale SRM has been done

‘ \ \ lor elements having intermediate and long-lived neutron

• , s t i on products. Concentrations of 30 elements can be

*' *

< 1 i iu d by 1 XAA

v
-*ii BCLb - Energy Related Air Pollutant Analysis Ins trument a t ion

Under the task Development of an Instrument to Measure Airborne

Sulfate Particulate Matter, field calibration results were

compared with laboratory calibration results. Laboratory results

showed considerable scatter, as well as systematic dependence on

both SO-, and relative humidity. In comparison to field calibration, in cases where sample is humidified and where S0 ? is present,

agreement with laboratory calibration was found to be good.

30 BCLc — Energy Related Pollutant, and Effects Monitoring and

Associated Methods and Techniques Development

Under the task Radiocarbon as an Environmental Tracer, the results

of the feasibility of mini-low level counting (lie) of radiocarbon

to distinguish anthropogenic from natural pollutant sources using

only mg sample sizes, have been published. Further -extention of

the capabilities of this technique in terms of sample size, throughput and quality control have been undertaken. Experiments to apply

the lie method to two specific environmental problems .have been

undertaken: (a) in Oregon, to resolve the contribution of field

and slash burning, wood stoves, natural emissions, fossil fuel

combustion etc., to the total particle load; and (b) in Washington,

a study to relate to the organic fraction in marine sediments.

Activities directed toward measurement accuracy and model validity

also have taken place. These applications served to increase the

discriminating power of the lie method through addition of chemical

and physical selectivity.

Also development of capabilities through the use of accelerator

mass spectrometry, large low- background proportional counters,

stable isotope analysis, and trace gas radiocarbon analyses were

also under invest igation

.

vi
SO BCMa — Energy Related Pollutants and Effects Monitoring an d

Associated Met hods and Techniques Develop ment

Under Energy Related Water Pollutant Standard Reference Materials,

material for the Estuarine Sediment SRM is being analyzed by

neutron activation analysis. Certification of a larger trace

element - in-water SRM is in progress.

A report, entitled "The Quantitative Removal of the Alkali and

Alkaline Earth Elements from the Trace Transition Elements in Sea

Water Using Chelating Resin, and its Application to Analytical

Instrumental Techniques," has been completed.

In the Inductively Coupled Plasma (ICP) technique, an operational

approach was chosen to examine the statistical behavior of all

channel -to -channel ratios during a normal analysis time period.

Results indicate that, with proper choice of an internal standard,

variability of response can be improved by a factor of two,

provided that the s ignal -to-background ratio for the analyte

element is ten or greater.

The procurement process for the production of an aqueous PAH

SRM is presently in progress.

A direct injector is being developed that places a , liquid sample

on the head of the capillary column, bypassing the normal heated

injection port, without adversely affecting chromatographic

resolution, and has been found to be solute boiling point

independent

.

Data on the work related to the phenols - in-water SRM have shown

that concentrat ions of phenol, o-cresol, and p-cresol remained

constant throughout a 27-month study. while the concentrations of

2-naphthol and 2 , 4 ,

6

- trimethylphenol were found to decrease with

vi i
tine. The most probable cause for such losses were attributed to

adsorptive losses to the walls of the glass ampoules. Also,

radiation sterilization was found not to be a practical means of

quenching biological activity.

80 BCN — Radiological Pollutant Quality Assurance

This work includes the completion of the calibration of natural

isotopic uranium and continuation of the measurement of the

half-life of plutonium- 241 . Fly Ash from combustion of eastern

United States Coal is being assayed for radium-226 and radium-228.

Tests on the radioactivity in SRM 1653, Trace Elements in Coal

Fly Ash, continue. Gamma ray measurements using Ge(Li) for the

determination of radium-228 are in progress. Six test sources

have been provided to QAB and one result reported to MBS

.

vii i
TABLE OF CONTENTS

Page

FORWARD ii

INTRODUCTION AND SUMMARY iii

LIST OF FIGURES xiii

LIST OF TABLES * xv

80 -BCKa- ENERGY RELATED POLLUTANT MEASUREMENT AND

INSTRUMENTATION DEVELOPMENT

1 Energy-Related Water Pollutant Analyses

Instrumentation 1

I. a Development of Marker Compounds 1

1 . b Application of Selective Detectors to Liquid

Chromatography 1

l.c Liquid Chromatography-Mass Spectrometry . . 0 . . . .

*1

1 . d Feasibility Study of Application of Particulate

Analysis by Ion Microprobe 6

1 . e Liquid Chromatography with Electrochemical

Detection of Qrganometallic Compounds . 10

l.f Laser Enhanced Ionization .... 10

80 -BCKb -ENERGY RELATED WATER POLLUTANT ANALYSIS

INSTRUMENTATION

1 Devel opment of Measurement Methods for Non-Volatile

Organic Pollutants in Water due to Energy

Technologies 2 3

Ra man Mi croprobe Characterization of Trace

Polynuclear Aromatic Hydrocarbons

~

’

1 —— ^ ! 2 3 . . l Do yel o pm ent of Specific Immunoassays for

Pi n i t rophcno 1 s in Water 2 3

PC -MS 27

1 C-LC 27

IX
Pa ere

1 . e Ion-Probe n —

1 . f Generation of Enhanced CARS Spectra of Organic

Liciuids in Capillary Waveguides w /

SO-BCLa-•ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

1 Development of SRMs for Stationary Sources

Associated with Energy Production 2S

1 .a NO ? in Air Gas Blend SRMs 28

1 .b S0 ? in N ? SRMs 28

1 . c NO in N ? SRMs 2 S

l.d 0 9 in N ? and CC^ in N ? SRMs 29

O Development of SRMs for the Monitoring of Ambient

Air Impacted by Emissions Resulting from Energy

Production 29

2 . a S0 o in Air 29

2 .b CO in Air 31

2 . c Automation of Gas Analysis 31

3 Develop Methods for Dispersal of Particulates on

Filter Media and Methods for Determining and

Controlling the Composition and Morphology of

Such Dispersed Particulates ! ! ! ! ^ ] ! ! . .... 32

3 . a NBS-SRM 1648 Urban Particulate Matter 32

3 . b Synthetic Ground Glasses Deposited on Filters .... 32

3 . c Thin Glass Films Produced by Focused-Ion Beam

Sputtering • 32

4 Particulate Physical and Chemical Characterization. . 33

4 . a . b . c Particle Donnler Shift Soectrometer (PDSS1 38

4 . d. e Development of Air Supported Plasmas 40

5 Particulates on Glass Fiber Filters 40

5 . a . i Ion -Chromatography 40

x
Page

5 . a . i i Lead, Sulfate, and Nitrate on Filter Media 49

0 Urban Air Particulate Washington D. C. Sample .... 50

7 Develop SRMs for Coal Conversion Processes and

Materials Balance Determinations 50

3 Development of an Oil Shale SRM 52

80-BCLb -ENERGY RELATED AIR POLLUTANT ANALYSIS INSTRUMENTATION

1 Development of an Instrument to Measure Airborne

Sultate Particulate Matter 57

80-BCLc-ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

1 Radiocarbon as an Environmental Tracer 62

80 -BCMa -ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

1 Energy Related Water Pollutant Standard Reference

Materials 79

l.a Complete Certification of Ocean Sediment SRM 79

1 . b . i Estuarine Sediment, Proposed SRM 1646 7 9

l.b.ii Preconcentration and Separation of Sea Water

Transition Elements 79

l.c Anions in Water SRM 80

l.d Anion SRM ............ 80

l.e Anion and Trace Elements in Water SRM 80

1

.

f The Role of Internal Standardisation in Analysis

or Aqueous Samples Using the Inductively CouplecT

Plasma (ICP) Technique . ! ! T-

! ! t ! . . . 80

2 SRMs for Organic Analysis ..... 85

2.

a/b Production of an Aqueous PAH SRM 83

l.c Development of a Pheno 1 s - in -Water SRM 85
Page

2 . d Development of SRMs for Organics in Sediment

and Biota S~

2 . e Spectroscopic Certification Technique for Analysis

or Trace Organics in Water SRM ] ] . ] . ] . ] ] ] . . 8

SO -BCMb -ENERGY RELATED POLLUTANTS .AND EFFECTS MONITORING AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

1 Develop Organic Standard Reference Materials for

the Calibration of Energy-Related Water Pollutant

Measurement Methods ] "

. ~

] ] I ”] ] ] ] ] ~ 7 . . 97

80 -BCN -RADIOLOGICAL POLLUTANT QUALITY ASSURANCE

1 Develop Calibrated Radioactive Materials for

Radiological Po l'lution~Associated with Nuclear

and Coal Energy Sources and Production 9 8

1 . a Solution of Natural Isotopic Uranium, and Solution

ot Plutonium-241 98

l.b Fly Ash from Coal Combustion 9 8

2 Measurement Traceability Studies with the Quality

Assurance Branch of EPA-LV . ! ] ] ] ] ] ] 7 100

APPENDIX I NBS Certificate of Analysis SRM 1648,

Urban Particulate Matter 54

APPENDIX II Resolution of Spectral Peaks: Use of

Empirical Peak Shape 74

APPENDIX III Advances in the Discrimination of Natural

from Anthropogenic Carbonaceous Pollutants

via Isotopes of Carbon 75

APPENDIX IV NBS Certificate of Analysis SRM 1645,

River Sediment 89

APPENDIX V Request for Bid Submitted to DOC for PAH SRM . 92

APPENDIX VI Report of Calibration — Uranium Solution of

Natural Isotopic Composition 102

APPENDIX VII Report of Test — Hydrogen- 5 Radioactivity

Test Solution 10

xii

1.0
1

o

3

4

5

6

7

S

9

10

1 1

i

;

1 3

1 4

1.1 NT OF FIGURES

Page

New type of I.C MS interface probe 5

A portion of the positive secondary ion mass

spectrum obtained l rom atropine applied to a bulk nickel substrate 8

A limited mass scan in the range 90-120 mass

units on a layer applied to a nickel particle. . . 9

Partial energy level diagram of lithium. ..... 13

Generalized energy level diagram used to model

LEI 15

Comparison of experimental LEI sensitivities to

the two-parameter theoretical fit value for

twenty-one transitions in fourteen elements. ... 18

Percent recovery of the 100 ppb indium LEI signal

with increasing sodium matrix, using 1 mm

diameter cathode rods 20

Percent recovery of 100 ppb indium LEI signal with

increasing sodium matrix, using cathode plates . . 21

Typical analysis of a suitably prepared sample

containing fluoride, acetate, chloride, nitrite,

phosphate, bromide, nitrate, sulfite, and sulfate. 41

Solubles in oysters . 44

Chloride and sulfur concentrations in oyster SRM

as determined by ion chromatography after

Schoniger flask combustion ....... 46

Pulsed FPD system response to ammonium sulfate

aerosols at various relative humidities with

and without SC^ added to the sample 58

Response of the pulsed FPD system in mV output

versus sample sulfui concent ration in yg S/m 3 for ammonium sulfate 59

Response of the pulsed 1 PI) system in mV output

versus sample sull ui > < nc en t rat ion in yg S/m 3 for sulfuric acid 6 0

XII'
Figure 15

Figure

Figure

Page

Anticoincident (R. r ) , meson (R,,), and guard

•A U p-i (R (cpm) versus run number for

g

)

coi nci dent

co unt rat

Wo od Samp

rta int ies

f 0 r c orre

ari son of

le utilizing Counter J. Poisson

(±la) are represented by error

16 Comparison of observed with expected vegeta

tive impact (fine particles)

17 Degree of RSD improvement over raw intensity

data examined at various signal to background

ratios for seven elements

66

70

82

xiv
LIST OF TABLES

Page

TABLE 1 Comparison of the Sensitivities Afforded by

Cerium Oxidative and Ultraviolet Detection of

Phenols in Liquid Chromatographic Effluents .... 2

TABLE 2 Intensity as a Function of Time on Two Replicate

Runs of 20 ym Diameter Particles 10

TABLE 3 Comparison of Detection Limits (ng/mL) . . 12

TABLE 4 LEI Detection Limits for Three Transitions in

Lithium 14

TABld! 5 Representative Real Sample Measurements 22

TABLE 6 Dinitrophenylated Proteins Produced . . 24

TABLE 7 Specificity and Titre of Antiserum to

Dinitrophenylated Conjugates 25

TABLE 8 Summary of Instrumental Conditions Employed

(Large Machine) 33

TABLE 9 Composition of Glass Films Determined by X-ray

Fluorescence Spectrometry 35

TABLE 10 Comparison of the Average Composition of

Sputtered Films Using Two Different Instruments

A and B 36

TABLE 11 Solubles in Oysters . 43

TABLE! 12 Chloride and Sulfur (as sulfate) Concentrations in

Oyster SRM as Determined by Ion- Chromatography

After Schoniger Flask Combustion 45

’EAE.EE. 13 .Summary Analysis of Filter Strips for Nitrate

and Sulfate by Ion- Chromatography 48

EUTE 14 Nominal Values of SO^, NO^, and Pb on Filters ... 50

‘ABIE IS NBS SRM Sub-bituminous Coal (1655) 51

TAB El 10 NBS SRM Fly Ash (1633a) 51

12 Approximate Elemental Concentrations in Shale Oil

as Determined by INAA 53

• : • : 18 Counter Backgrounds 64

* ; 19 Standards and Reference Samples 67

xv
Page

TABLIi 20 Modern Carbon in Portland Aerosols o9

FABLE 21 Comparison of Normal and Splitless Injector

Techniques 84

TABLE 22 Boiling Points of Some Polynuclear Aromatic

Hydrocarbons 84

TABLE 25 Stability of Selected Phenols in Distilled Water. . 86

TABLE 24 Degradation of Aqueous Solutions of Phenols Due to

Radiation Treatment 88

TABLE 25 Radiological Pollutant Quality Assurance 99

TABLE 26 Status of Traceability Studies of Radioactivity

Measurements by the Quality Assurance Branch

(EPA-LV) for the Period of July 1 through

December 21, 1978 101

APPENDIX III

Table 1 Isotopic Source Indicators 77

APPENDIX VI

Table 1 Summary of the Isotopic Composition and the Atomic

Mass 103

Table 2 Uranium Concentration Data 103

Table 3 Relevant Conversion Factors and Constants 103

Table 4 Calculated Isotopic Uranium Radioactivity

Concentrations, October 1978 104

xvi
• ' ''la - a - ENERGY RELATED POLLUTANT MEASUREMENT AND INSTRUMENTATION

DEVELOPMENT

i no rgy - Related Water Pollutant Analyses Instrumentation

i . n Development of Marker Compounds

Activity in this project must await development of the master

analytical method by EPA/ERL/Athens

.

1 . b Application of Selective Detectors to Liquid Chromatography

The cerium oxidative detection system is in principle a highly

sensitive and fairly selective means for the detection of phenols

in the effluent of a liquid chromatograph. Katz and Pitt (Anal.

Lett., _5 , 177 (1972)) first developed the "cerate oxidative

monitor" for the detection of organic acids and other oxidizable

components in body fluids. The column effluent is mixed with

cerium(IV) reagent solution — cerium(IV) sulfate and sulfuric

acid — by means of a magnetic mixer before entering the reaction

section, which consists of coiled Teflon tubing (with an internal

volume of 4 mL) immersed in boiling water. At a flow rate of

29 mL/min employed for the anion- exchange separation of aromatic

acids, the residence time in the reaction section is about 12

minutes. A fluorometer monitors the fluorescence emission of the

cerium(III) produced in the reaction.

•-'lloff and Larose (J. Chromatogr., 9_9, 731 (1974)) employed a milar cerium fluorescence detector for the reversed -phas e HPLC

m: a 1 vs is of phenols in water. These workers used a peristaltic

s : r t ion ing pump to add the reagents to the column effluent in

- to reduce peak broadening in the HPLC separation. Using

' s'-'sten, concentrations of about 10 ppb of phenol could be

*--•2.. but the response generally decreased as substitution on

- v.ep.e lie ring increased.

i
This detection system offers sensitivity because cerium III

fluoresces strongly at 363 nm and selectivity (in addition to the

chromatographic selectivity afforded by the column) because only

ox id i cable species arc detected and reaction conditions can be

optimized for a given class of compounds by controlling variables

such as reaction time and temperature, and the nature and concentration of redox reagents.

The data given in Table 1 shows that detection limits obtained

using ultraviolet detectors were lower with the added advantage

that the integrity of the separation need not be sacrified since

no reaction coil is necessary.

TABLE 1

Comparison of the Sensitivities Afforded by Cerium Oxidative

and Ultraviolet Detection of Phenols in

Liquid Chromatographic Effluents

Ng injected into analytical system

phenol p-c resol o- cresol 2 -naphthol

Filter photometer 254 nm 2.6 5.5 3.7 0.4

Spectrophotometer 254 nm 12 23 14 4

Spectrophotometer at

optimum wavelength

3.1 3.6

(270 nm) (275 nm)

3.3

(270 nm)

1.7

(275 nm)

Cerium oxidative monitor 10 13 17 19

2
In a previous report we have described the use of an electrochemical detection system for IIPLC detection of phenols . This

\-.tein has superior sensitivity (detection limit less than 0.1 ng)

\J.ien compared with the cerium oxidative monitor and UV detectors

11U ] offers selectivity at least comparable to that afforded by

i he cerium oxidative monitor.

Though simple in principle and potentially sensitive and selective,

there are other factors that detract from the utility of this

system:

a) Cerium IV is unstable when in contact with fresh glass

or heat and is oxidized to the fluorescent cerium III which

causes background fluorescence..

b) The relationship between concentration and response is

not always linear, probably due to the uncontrolled production of fluorescent oxidation products that also contribute

to the signal measured.

c) The volume between the exit of the chromatographic

column and the detector must be sufficiently large to allow

reaction of the phenols with the Cerium(IV), a sulfate.

We used a 2 mL reaction coil. This caused chromatographic

band broadening and hence severe losses in resolution.

Because of combinations of these three factors, we found that we

tould not detect less than 10 ng phenol.

3
Irnther experience with the LC-MS interface probe lias shown that

the permanently-constricted tube is too easily plugged with

particles in the liquid flow. A new type of probe was constructed

(figure 1) with a constriction consisting of a 0.075 mm tungsten

wire passing through the probe tube. The new probe tube has an

01) of 1.0 mm and an ID of 0.10 mm. The tungsten wire has a footbal 1 - shaped ball of silver solder on the end about 0.5 mm

long and 0.3 mm in diameter. By moving the tungsten wire, the

seating of the ball in the orifice at the end of the probe can be

varied and the' flow rate can be varied from approximately 10 yL/min

to less than 1 yL/min. This provides a convenient adjustment of

the flow rate and will stop the influx of air when the probe is

not in use. In use, the flow rate is set so that the pressure

- 4 above the turbomolecular ion source pump is about 1 x 10 Torr.

It was discovered that less volatile compounds were not carried

into the hot source effectively by the n-pentane solvent. We

attribute this to vaporization of the solvent before it reaches

the constriction of the probe tip. The use of iso-octane as the

solvent gave much better results.

A liquid chromatograph was set up and the effluent was fed to

the heated wire interface. The sample contained 3 -methylnaphthalene

,

phenanthrene , fluoranthene, chrysene, and benzo (a) pyrene . An

aminosilane. column with 5 percent methylene chloride in isooctane as the mobile phase was used for the experiment. Good

separation of these compounds was obtained, and the mass spectrometer detected the first three satisfactorily. Detection limit

for phenanthrene was estimated to be less than 100 ng injected

into the chromatograph. It is expected that this will improve

markedly when the mass - spectrometr ic parameters are optimized.

The probe has been further modified to surround it almost to the

tip with a copper heat sink. Calculations show that the tip

temperature should not exceed 50 °C with this heat sink. Parts

are on order which will enable us to measure source temperatures,

and the source -has been modified to incorporate heaters which

will make it possible to control the source temperature.
c

o <uu

+J -H

<L>

• fi<>—

<D O O

03 b

Figure

1.

New

type

of

LC-MS

interface

probe.
(Vir. i Jo rat ion has been given to methods for a feedback control of

1

, Trover input to the evaporator wire. This should make it

, jpio to control the amount of evaporation on the wire so that

o>) percent concentration can be obtained in spite of small input

i l ow variations.

] . d Feasibility Study of Application of Particulate Analysis by

Ion Mi. crop robe

In the previous semi-annual report on the NBS/EPA Energy Environment

Project (Sept. 1978) we reported preliminary results on the application of the ion microprobe (a focused beam form of secondary ion

mass spectrometry) (SIMS) to the study of thin organic layers on

substrates. Benninghoven and co-workers (University of Munster)

had previously demonstrated that secondary ions corresponding to

the parent organic compound as well as characteristic fragment ions

could be successfully sputtered under ion bombardment conditions

selected to minimize damage to a specimen: (a) inert gas primary

ion such as Ar

+

; (b) ion beam energy, typically 2 keV; and most

important, (c) low primary ion beam current density, typically

10 A/cm . These conditions are said to be "static SIMS" in which

the specimen is unaltered by the measurement process. In order

to obtain an adequate total signal with such a low current density,

2

an area in the range 0.1-1 cm must be bombarded. While Benninghoven '

technique is satisfactory for the characterization of organic layers

on a large substrate, or possibly on a large aggregate of particles,

it is clearly not adequate for the characterization of organic

layers on single particles.

In the previous report, we demonstrated the possibility of

obtaining results similar to these reported by Benninghoven et al.

under primary ion bombardment conditions which were more typical

of the ion microprobe: (a) reactive gas primary ion, ^0? +

; (b) high beam energy, 18.5 keV, and (c) primary ion current densities

- 6

7 an the range 10 A/cm~. Parent compound and characteristic ion

6

i
fragments were detected from glycine on a nickel substrate

and 5 - f luorodopamine on a gold substrate.

These studies have been extended to the area of particulate

analysis by measuring secondary ion mass spectra from organic

layers applied to metallic particles (commercial purity nickel

and silver) with a size range 20-60 pm diameter. The primary ion

beam conditions employed were: (a) primary ion species, ^ C> 2

+

; (b) beam energy, 9.50 keV (which corresponds to 4.25 keV monotomic

- 5 2 oxygen bombardment); (c) current density, 2.8 x 10 A/ cm (1 nA

into a 60 x 60 pm square scan) . Figure 2 shows a portion of the

positive secondary ion mass spectrum obtained from atropine

(C^yH^NO-) applied to a bulk nickel substrate. An ion signal

was observed at 289 mass units which presumably corresponds to the

parent ion. Most of the signals observed in the spectrum correspond to the substrate and its contaminants . Upon scanning the

region from 9.0-120 mass units on a fresh area (offset portion),

a large number of peaks corresponding to organic fragments are

observed. This experiment points out the difficulty in obtaining

useful spectra w

r ith a sequential spectral measurement. The

destructive nature of SIMS leads to a destruction of the organic

target. Figure 5 shows a limited mass scan in the range 90-120

mass units on a layer applied to a nickel particle. A pattern

similar to that observed from the bulk target, Figure 2, is

found. Peak- to -background ratios as high as 100:1 are observed

for these ions in both the particle and in the bulk.

A similar experiment was conducted with 5- f luorodopamine applied

to 20 pm diameter silver sphere. Spectra similar to the 5-fluorodopamine spectrum shown in the previous report (Figure 12) were

obtained from the layer on the particle. The intensity of the

parent ion at 1~1 mass units was found to be a strong function

of the ion dose (bombardment time) . Table 2 gives the intensity

observed as a function of time on two replicate runs of 20 urn diameter particles.
figure

2.

A

portion

of

the

positive

secondary

ion

mass

spectrum

obtained

from

atropi

))o

applied

to

a

hulk

nickel

substrate.
- r3t

•10 - Atropine

Nickel particle substrate

8-5 keV

Positive secondaries

Figure 5. A limited mass scan in the range 90-120 mass units

on a laver anplied to a nickel oarticle

o
TAB LIZ 2

Intensity as a Function of Time on Two Replicate Runs of

20 um Diameter Particles

Time Intensity at 171 mass units

sphere # 1 sphere *2

2 seconds 1073 1052

4 246 495

6 179 351

8 135 253

10 106 151

12 127 128

14 104 105

16 86 98

This strong decrease in signal is due to Cl) rapid sputtering of

the organic layer and (2) beam damage of the organic compound.

Further experiments are being carried out to enlarge our experience

with organic SIMS.

1 . e Liquid Chromatography with Electrochemical Detection of

0 r g an o metal lie Compounds

A comprehensive report entitled, "Development of Methodology for

the Measurement of Trace Organometal Species by Liquid Chromatography

with Electrochemical Detection," has been completed and will be

submitted to EPA for publication as an EPA Technical Report.

l.f Laser Enhanced Ionization

Introduction

Previous reports over the past three years have described the

origination and early development of laser enhanced ionization

for trace metal analysis in flames. The method uses a uulsed

r*

10
or chopped tunable dye laser to selectively excite analyte

atoms in the flame. A current passed through the flame via

external electrodes and the burner head is seen to change in

response to the laser excitation. The laser- induced current is

separated from the dc background current by a simple RC network,

amplified, and signal averaged following gated or synchronous

detection. Sub-ng/mL detection limits and linear response over

at least four orders of magnitude are currently obtained for

over a dozen elements in water.

The second half of 1978 was devoted primarily to 1) continuing

refinements in the detection limit table, 2) completion of a workable theoretical model to explain and predict experimental

sensitivities, and 3) initial real sample measurements.

Limits of Detection

All of the limits of detection obtained to date are shown in

Table 3, along with comparative limits by other flame techniques.

Limits obtained during the period of this report (distinguished

by footnote "c" in the table) are Ag, Ba, Bi, Ca, and Li.

As shown by footnote "d" in Table 3, twelve of the eighteen have

equivalent or superior detection limits by LEI, in comparison to

the best reported results by atomic absorption (AA) , atomic

emission (AE) , atomic fluorescence (AF) , or laser-excited AF . Of

the thirteen elements with ionization potential (I?) < 7 . 3 eV

,

only Ca, Cr, and K are better detected by another method.

For these elements, much weaker transitions were used for the LEI

measurement than for the other methods

Of particular interest is the work done with lithium, detailed in

Table 4. The 1 pg/mL (one part -per - tril lion by weight)- detection

limit of Table 3 is the best yet measured for the method. The

transition used was the traditional 2s “S—2p ~P° at 6 ” 0 .nm , as shown in Figure 4

II
TA3LE

Cl Comparison of Detection Limits^ (ng/mL)

(46,8 5)

Element LEI AA AE AF Laser AF

Ag (7.6)

b

1 C1

? .1 4

d Ba (5.2) 0. 2 C 20 1 — 8

d Bi (7.3) 2 C 50 20000 5 3

Ca (6.1) 0 .

1

C

1 . 01 20 .08

Cr (6.8) 2

? 2 5 1

Cu (7.7) 100 1 0.1 0.5 1

d

Fe (7.9) 2 4 5 8 30

d Ga (6.0) 0.07 50 10 10 0.9

d

In (5.8) 0 . 006 c 30 0.4 100 0.2

K (4.3) 1 3 .05 — —

dLi (5.4) 0. 001 C

1 .02 — 0.5

dMg (7.6) 0.1 0.1 5 0 .

1

0.2

dMn (7.4) 0.3 0 . 8 1 1 0 .

4

dNa (5.1) 0 .05 0 . S 0 .

1

— 0 .

1

Ni (7.6) 8 5 20 3

dPb (7.4) 0.6 10 100 10 13

Q Sn (7.3) 6 20 100 50 —

aTl (6.1) 0.09 20 20 8 4

3

LEI in CoH ,/air flame ; others in best flame available

.

b TIonization potential in p a r e n t h

e

ses (eV)

.

c

>:e\v LEI re suit (since last rep or t) . "LEI best method.

1:
State Energy

Ionization Potential

43,487 crn'l

31 ,283 cm*

14,904 cm'1

0 cm*1

Figure 4. Partial energy level diagram of lithium.

15
TABLE 4

LEI Detection Limits for Three Transitions in Lithium

have length nm~) No. Photons Trans it ion LOP (ng/mL)

670. S 1 2s ~S -2p - po 0.001

610.4 1 2p

2 P°-3d

7"D 0.012

639.3 oLm 2s

2 S -3d

7 0.4

A detection limit of 12 pg/mL for the excited Zp""? 0 —3d“D transition at 610.4 nm illustrates the surprising sensitivity of the

method for excited state transitions. The detection limit is

only 12-fold worse than the ground state transition in spite of

_ _ 4 7 _ a Boltzmann population of ^10 ror the 2p"P level. This exfect

is further discussed along with the mechanism studies below.

A final surprising result from lithium is the 0.4 ng/mL detection

-) limit for the two photon 2s~S—5d"D transition using 639.3 nm ligh

Although of no practical value for Li detection, the result

illustrates a method of extending laser enhanced ionization to

elements of high ionization potential. Two UV photons — from a suitably high-powered frequency-doubled laser — could be used to

excite energy levels up to ''--10 eV above ground. The effective

single-photon wavelength of such transitions is in the vacuum

UV, and cannot be reached directly with current laser technology.

Mechanism

The model for the production of LEI signal is based on the generalized energy level diagram of Figure. 5. Levels 1, 2, and 3

represent the lower and upper levels of the optical transition,

and the ion ground state, respectively. The E- , n- , and g. are
ENERGY

POPULATION

STATISTICAL WEIGHT en o

csi es

d o

<o s

CS! S O

c/i . W

UJ < C/3

C/3

LUO

pi CS

£5

LW<w

to

LU

to

00

LU

t«3 £» O a esa. >

>s

=COM

u~~. a

CO

uu

esi LU UJ

=0
the corresponding energies, number densities, and statistical

weights. (E- is thus the ionization potential, and n~ the ion

number density.) , B^,, and B-,

1 are the Einstein coefficients

for spontaneous emission, absorption, and stimulated emission;

I is the spectral irradiance of the laser; and k 7 ^ and k ? - are

collisional rate constants for quenching (de - excitation) and

ionization from the excited state. Additional processes which

occur are omitted as being of secondary importance.

The LEI signal current, S, is proportional to the rate of ionization from the excited state:

dn,

o dt

CD

The excited state population, in turn, is a function of the laser

intensity. In the absence of optical saturation,

'K, B

l 2

I (N- n

5

) A

21

+ 21

( 2 )

where N = n^ + n ? + n~ is the total analyte number density in the

flame. Combining (2) and (1),

dno dt

B

l 2 I(N-n3

) A91 + k 7

, (5)

If n~<<N for all time, that is, if the laser converts a trivial

fraction of the analyte atoms to ions during the pulse, the peak

signal current, S , can be seen from (3) to occur at the peak

laser intensity, I , or

m

m

1 _ t J o 1 - m

( 4 )

16
which is linear in power, absorption coefficient, and ionization

probability. A more general solution of (3), however, yields

for the maximum current

S « n

m

12

I m

X

( 5 )

where 0<X<_1, and the less - than-linear response to power, absorption, and ionization probability results from "electrical

saturation", i.e., the conversion of a significant fraction of

the analyte to ions during the pulse.

The model of equation (5) was fitted to a data set of sensitivities [signal current per unit concentration) for 21 transitions

in 14 elements. The fit yielded an exponent of X = 0.63 ± 0.05

for equation (5), indicating that our flashlamp -pumped dye laser

does indeed convert an appreciable fraction of the' analyte to ions

during the 1 us pulse. .Figure. 6 shows a plot of the experimental

sensitivities versus the fitted sensitivities, with a spread of

<1 order of magnitude for data over a range of >4 orders of

magnitude

.

Application to Real Samples

The most severe problem encountered to date in the application of

the method to real samples, has been the effect of high background

ionization on the signal. When easily ionized elements are

present in high concentration in the sample, they greatly increase

the background ion/electron density in the flame. In such circumstances, the positive ion sheath, or spare - charge , — which always

exists near the cathode — is greatly enhanced, and the available

electric field at the laser-excitation site is diminished.

1

"
EXPERIMENTAL

SENSITIVITY

(nA/ppb)

IS
The extent of the problem when 1. mm diameter tungsten rods are

used for the cathode is shown in figure 7, for a 100 ppb indium

solution with increasing sodium matrix. During the present

reporting period, an order of magnitude improvement was achieved — as shown in figure S — by the simple expedient of replacing the

cathode rods with flat molybdenum plates. The positive ion sheath,

and hence the matrix effect, is reduced by the inverse of the

lightning rod principle — for a given applied potential, the field

strength is less at a flat surface than at one of positive

curvature

.

The presence of easily ionized matrices is checked simply by

comparing the background (dc) current with and without the sample

being aspirated into the C ? H ? /air flame. With the signal modified — but not eliminated — by easily ionized matrices, accuracy may be

assured by using the method of standard additions. An alternative

method, for small differences in background current, is to increase

the fuel to the flame, thereby raising the background current to

a point such that the change due to the sample is negligible. Then,

the increased ion/electron density affects the sample and calibration standard measurements equally. Table 5 shows examples of

three types of real sample measurement: 1) no matrix effect, neat

calibration standards, 2) small matrix effect, fuel-rich flame

used with neat standards, and 5) large matrix effect, standard

additions used.

19
100

ppb

In,

Cathode

Rods

in

£

CL

CL

o

f—

<

oc

bLlJ

o

z

o

o

Q

o

in

o

C\J

o o o c o o

CD CC CO

^

C\J

Ad3A00Jd !N30d3

:o

igure

7.

Percent

recovery

oi'

100

ppb

indium

1.1:1

signal

with

increasing

sodium

matrix,

using

1

mm

diameter

cathode

rods.
SODIUM CONCENTRATION (ppm)

Figure 3. Percent recovery of 100 ppb indium LEI signal with increasing

sodium matrix, using cathode plates.
TABLE 5

Representative Real Sample Measurements

Element Wavelength Samole LEI Expect ed a Comments

In 3 0 5.9 Mi -based Alloy 35 5 7 1

Mn 504.

River Sediment 786 770 2

Mn 304 .

SRM 1261- Steel 6700 6600 3

Comments

1. No matrix effect; calibration via neat standard

solutions

2. High background current; calibration via standard

additions

5. Moderate background current; matrix effect compensated

by using fuel-rich (high electron content) flame for

both sample and neat standard solutions.

Conclus ions

Laser enhanced ionization in flames has been demonstrated at

sub-ppm levels for eighteen elements in water, with the best

case extending to the part-per- trillion level. A model for the

signal production mechanism has been shown to adequately describe

observed sensitivities, and may be used to predict sensitivities

for other elements and transitions. Matrix effects have been

reduced an order of magnitude with a simple change in electrode

shape, and five percent accuracy has been achieved with a small

but representative selection of real samples.

Future directions will include 1)' the extension to high ionization potential species with multiphoton or stepwise excitation,

2) further studies of optimum electrode structure for minimum

matrix effect, 5) comparison of different laser systems, and

1) characterization of tbo electron/'ion transport process.
80 -BCK-b- ENERGY RELATED WATER POLLUTANT ANALYSIS INSTRUMENTATION

1 Development of Measurement Methods for Non-Volatile Organic

Pollutants in Water due to Energy Technologies

1 . a Raman .Microprob e Characterization of Trace Polynuclear

Aromatic Hydrocarbons

No activity in this project during the present reporting period.

1 . b Development of Specific Immunoassays for Dinitrophenols in

Water

Because the sensitivity and selectivity of immunoassays for a variety of ligands offer many possibilities of separation and

detection, we have started a project to develop assays for one of

the priority pollutants, 2 , 4 -dinitrophenol (DNP) . Existing procedures evaluated at NBS have shown that gas chromatography and high

performance liquid chromatography, while suited for analytical

determinations of most of the toxic pollutants, are not as

efficient in the separation and identification of the nitrophenols

.

Immunoassays require highly specific antibodies produced in

animals, usually rabbits or goats. Antibodies with specificity

for small molecules such as DNP are made by chemically conjugating

the DNP group to a specific protein and injecting the conjugate

into the animal. Although commercially prepared antisera to DNPproteins are available, we found that custom-prepared antisera

were more economical and of higher quality.

We produced DNP - con j ugat ed proteins to be used in the assay of

purchased antisera, or to be injected as immunogens to produce

specific antisera. Listed in Table 6 are the antigens produced.

_ j
TABLE 0

Dinit rophenylated Proteins Produced

Protein

Rabbit Albumin (RSA)

Bovine Albumin (BSA)

Bovine Gamma Globulin

Ovalbumin (OVA)

Coni ugat

rsa-dnp

6

rsa-dnp

1]L

RSA-DNP,

,

lo

RSA-DNP

1S

RSA-DNP 25

bsa-dnp.,..

L j

BSA-DNP ? s BSA-DNP c , 54

(BGG) BGG-DNP

6

0VA-DNP ?

Antisera with specificity for DNP were either purchased from

stock or custom prepared for NBS. Two different conjugates were

used as immunogens in the custom preparations. All antisera were

then assayed for specificity and titre by two methods: double

gas diffusion and passive hemagglutination. Results of these

assays are listed in Table 7.

These data illustrate the wide variability in specificity and

quality of the antisera. Choice of appropriate antisera for

immunoassays depends on a combination of factors, with titre

(reciprocal of greatest dilution factor giving positive response),

or relative amount of specific antibody (IgG), being an important

parameter for subsequent incorporation of the serum into a working

24

assav
TABLE 7

Specificity and Titre of Antiserum to

Dini trophenylated Conjugates

Gel Diffusion Passive Titre Hemagglut i nation

vs 0.5 mg/mL

Source bsa-dnp ?3 UNCONJ BSA BSA-DNP^

2 o RSA-DNP

Commercial

Lab A - Rabbit 1 : 4 10 10 160 10

Lab A - Goat 0 40 40 160 80

Lab B - Rabbit 1:4 0 320 640 80

Custom- Produced

3A- 1 1:8 0 160 128 0 80

3A- 2 1:16 0 0 1280 20

3A- 3 1:8(+) 10 40 640 80-

3B-1 0 10 10 10 10

3B - 2 0 10 10 10 10

The ultimate goal of detecting parts per million (ppm) or parts

per billion (ppb) of DNP in water will have to be achi eved with

very specific antibody used in a competitive binding type of

assay. Immunochemical tests performed with the crude antisera

using free DNP as an inhibitor of gel diffusion or passive hemagglutination demonstrated the problem. Using gel diffusion, the

. ? minimum free DNP detectable was 1 x 10 mol/L or about 2,200 ppm.

Passive hemagglutination was inhibited by 6.3 x 10

4 mol/L or

about 140 ppm. Neither inhibition method was sensitive enough to

be considered as a viable assay for free DNP in water.

Inhibition studies, however, were useful in directing the ultimate

method of assay procedure. Binding characteristics of serum *3.4.2
were studied by inhibiting gel reactions with a variety of DNPlabeled compounds. Affinity for the DNP ligand is weak, while

affinity for the homologous antigen ( BSA- DNP

)

is strongest in

the following series:

DNP<p - amino benzy 1 -L - glut amate - DNP< glycy lglycylglyci ne-DNP< lysine - dnp<bsa-dnp 9 ,

2 a

Development of a ligand binding assay using tritiated DNP (°H-DNP)

was started. Whole antisera was used in the initial study as we

developed optimum conditions for separation of the bound vs. free

fractions of labeled ligand. Charcoal separation (0.1% Norit)

was 96 percent effective in separating the free ligand from the

bound. Similarly, a purchased commercial preparation was evaluated

for separating the bound ligand on the IgG antibody from the free

ligand in solution. Both methods showed some promise for separation but were not satisfactory for assay because the binding of

the ligand to the specific antisera was riot significantly different

from binding to the normal control sera. This non- specif icity

may be due to the presence of many other proteins in the sera.

We have now' fractionated the sera to isolate the immunoglobulin,

IgG. These fractions are being evaluated and will be bound to

plastic tubes for use as solid-phase reagents. We have developed

for this procedure protein detection methods suitable for detecting microgram quantities of IgG bound to tube surfaces.

Better sensitivity of a solid phase assay may depend on displacement of a different ligand than 0 H-DNP. We are procuring a small

14 amount of C-DNP-lysine to be used in the method.

Additional experiments are now being carried out to optimize the

binding of IgG onto either polypropylene or polystyrene tubes.

These will be followed by binding experiments with the labeled

DNP compounds. We also anticipate measuring quenching of antibody

fluorescence as it binds with the DNP hapten.

26
l.c LC - MS Covered under section SO-BCK-a, l.c.

1 . d L C - E C , Covered under Section S0-3CK-a, l.b.

l.e Ion -Probe , Covered under section 80-BCK-a, l.d.

1 . f Generation of Enhanced CARS Spectra of Organic Liquids in

Capillary Waveguides

Recently we have developed a new approach to analysis of organic

compounds in liquid phase by Raman Spectroscopy. Enhancements

of up to a factor of 130 have been demonstrated in the Coherent

Anti-Stokes Raman Spectroscopy (CARS) output from a sample in a liquid- filled dielectric waveguide compared to the signal

obtained from the same material in a cuvette. The waveguide CARS

experiments show this large enhancement in sample volumes of about

0.75 yL. Thus, the advantages of CARS, namely fluorescence

rejection, low average power input, and spatial filtering can be

maintained in the waveguide in very small volumes. This technique

can be adapted to a flow through geometry to be coupled to HPLC,

for example, to improve the detection sensitivity of such systems.
SO-BCL-a-ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

Development of SRMs for Stationary Sources Associated with

Enenzv Production

l.a NO-, in Air Gas Blend SRMs

The results obtained on periodic analyses of two concentrations

of nitrogen dioxide in air (reported in September 1978 semiannual report) suggests a degree of stability which may be

satisfactory in terms of an SRM. However, the small number of

available samples makes it difficult to fully evaluate these

mixtures over the desired concentration range of 250 to 2500 ppm.

Consequently, a large number of cylinders at nominal concentrations of 250, 500, 1000, and 2500 ppm have been ordered. The

mixtures at 250 and 2500 ppm should be received and a preliminary

analysis completed by March 31, 1979. The 500 and 1000 ppm

mixtures should be received and analyzed by June 50, 1979.

Subsequent analyses may be necessary to establish stabilitybut the number of such subsequent analyses and the time period

involved will depend to a great extent on the results of the

preliminary analyses.

l.b SO-, in N, SRMs

No work was done during the last six month period in this

project. We must await funds for purchase of material.

l.c NO in N, SRMs

Work on this project will be completed in the next few months

but is being funded by MVMA.
l.d 0 in N 0 and CO^ in N 0 SRMs

No work was done during the last six month period in this

project. Material has been ordered (2 and 10 percent 0 ? in

|2

J

.

2 Development of SRMs for the Monitoring of Ambient Air

Impacted by Emissions Resulting from Energy Production

2 . a SO^ in Air

The study of the feasibility of a low concentration sulfur

dioxide in air compressed gas SRM has been completed. While

it app>ears that some individual aluminum cylinders containing

mixtures of sulfur dioxide in air at concentrations below one

part per million (ppm) may have reasonable stability, similar

cylinders in the same concentration range were found to be instable. The instability appears to depend on the condition of

the individual cylinder, and is of sufficient magnitude that

such mixtures would be unsatisf actory as SRMs. However, the

rate of loss of sulfur dioxide is such that cylinders containing

mixtures of sulfur dioxide may serve as satisfactory laboratory

standards, provided that the concentration is periodically

determined on a relatively short time basis.

Another problem which was observed with these mixtures results

from adsorption of small quantities of sulfur dioxide in the

cylinder valves. The aluminum cylinders employed in this study

were equipped with stainless steel valves. It was necessary

to flow the mixture out of the valve at either a high flow rate

or for a very long period of time in order to reach equilibrium.

For example, a sample flowing at a rate of 1.5 L/min had not

reached equilibrium after a period of 30 minutes. Conversely,

a mixture in the same concentration range generated with a

^ Q
permeation tube and flowing at 1.2 L/min readied equilibrium

within 9 minutes. Flow through the valve at a rate of 2.5 L/min

would require about 20 minutes to reach equilibrium.

It was possible to minimize all

equilibration process by proper

tioning but it was not possible

cylinder valve.

external fact

choice of mat

to eliminate

ors in the slow

erials and by condithe influence of the

Thus, it appears unlikely that gas mixtures of this sort

serve as satisfactory SRMs . However, with proper select

monitoring of individual cylinders, and with an awarenes

critical nature of the flow through the valve it is poss

use them as secondary standards.

would

ion and

s of the

ible to

N0 ? in Air

There have been no further developments

that would offer any hope for preparing

dioxide in air at concentrations below

be satisfactory as SRMs.

in the gas industry

concentrations of nitrogen

the 1 ppm level that would

NO in N

2

Further measurements of the four mixtures previously analyzed

confirm the anomalies reported earlier. It appears from the

results obtained thus far, that there is an initial slow decline

in the concentration of nitric oxide. As the pressure within

the cylinder decreases, nitric oxide previously adsorbed on the

walls is desorbed and a slight rise in concentration occurs.

This effect will be confirmed by further analyses during which

all four samples will be bled to approximately atmospheric

pressure. If the effect is real it will mean that mixtures in

this concentrat ion range would not be suitable as SRMs.

50
Z.b CO in Air

Further e cylinders

hvdrocarb

batches o cylinders

Substi tut

cylinders

samples o lot, indi

of the me

evidence

cylinders

xamination of samples of carbon monoxide in air in

lined with ceresin wax has revealed the presence of

ons at concentrations higher than expected. Previous

f carbon monoxide in nitrogen contained in wax lined

did not contain detectable quantities of hydrocarbons,

ion of aluminum cylinders for the wax-lined steel

appear to have resolved this problem. Analysis of 26

f 10 ppm carbon monoxide in air, prepared as a single

cates complete homogeneity within the limits of precision

thod of analysis (±0.12% relative). This is rather good

of the essential stability of the mixture in aluminum

2 . c Automation of Gas Analysis

The Computer Operated Gas Analysis System (COGAS) has been

modified and programmed to analyze gas SRMs using gas chromatographic and other discontinuous analyzers. The system works as

well for discontinuous analyzers as it does for continuous

analyzers, such as non -dispers ive infrared instruments. It

is now used routinely for certification of all gas SRMs, with

the exception of permeation tubes and high concentration sulfur

dioxide in nitrogen standards.

Work is in progress to expand COGAS from a cylinder capability. In addition, work is

a different program, to construct a system

bration of permeation tubes utilizing simi

programming as was developed for COGAS.

twenty to a fifty

in progress , within

to automate the calilar hardware and

51
Develop Methods tor Disnersal of Particulates on Filter

Media and Methods for Determining and Controlling the

Composition and Morphology of Such Dispersed Particulates

5 . a NBS-SRM 1648 Urban Particulate Matter

SRM 1648 has been certified (see Appendix I).

5 . b Synthetic Ground Glasses Deposited on Filters

There has been no activity in this project during the past

six-month period.

5 . c Thin Glass Films Produced by Focused-Ion Beam Sputtering

In the previous report covering the period from January 1 to

July 1978 we described our work in the following areas: (1) Depo

sition of NBS-SRM 1648 particulate matter, (2) Grinding of synthetic glasses prior to deposition on filters, and (5) thin

films of glasses prepared by the focused ion-beam sputtering

technique. From July 1978 to December 30, 1978 our work was

directed totally to the preparation and characterization of glass

films prepared by sputtering and the results of this work are

described in this report.

The 17.8 cm glass target used in these sputtering experiments

was fabricated and ground to a thickness of 2 mm at NBS . The

elemental composition of the target was the same as used in

previous work described in the report of July 1977 and consisted

of 56. 0^ Si0 7 , IS . 0% CaO, 20 ZnO, and 2 6% PbO. A series of

experiments was performed in which the major instrumental

parameters, such as ion- acceleration voltage and ion-beam current

were systematically varied to determine their effect on the

elemental composition of the glass films. Table 8 is a summary

— o
Summary

of

Instrumental

Conditions

Employed

(Large

Machine)

•J) xr o o O o o \ ~T H H —1 o u 3 \ \ \ \ i—i o C'i —•j dC •—_ -—;

CO CTi CTi CTi LO

r—t

•M i i 5

<•* <-* Ss < % ! % r— ^ ~ ! o n LD LO LO LO CO CO T OO •—«

h- rH

VO CO LO \C o v pp

4-> XI HI XI H] XI HJ \ \ \ \ x \ 0) \G V0 o o sO o 2 ^T ^r h- HT H" o

CDO o o • CcQ o o o o LO

O i

1 Cd CO CO CO o rH o U -H 1 V , 1 . i o 1 LO U r—I o o o w O »> < o o o o pH o pH > x- r^- x* orH

CO co CO CO CO CO

CO 1 i i p 1 1 1 o o o o o o XI rH pH rH pH rH rH o g X X • X X X

C3 r—1

r—t

rH rH rH pH

OO CO OO CO CO CO CO 1 1 l 1 I 1 H ~ o O o o o o < rH pH rH pH rH pH X X X X X X = x* tH H- tx fp

5-i • O

Cd 4-> vO vO MD sO CO ~ cd • • • IS • 1 1 • CO 5_ XI HI XI HI XI • cd 0 *

s \ \ •p

rH

x

x

C

OOO o o o

Cl, CDO

O \o lO vO CTi

O

LO LO LO LO LO CM • .jvi'tf; • • • +> in LO LO LO LO LO C \ \ \ x 0 LO LO LO LO LO L0 • . • . • pH

cd ^r HT xr xr

r—•

XI HI XI CO XI • H 1 1 i 1 , O lC sO lO

r—1rH rH p—1 0 * S co XI •=r co LO •H 5-1 • • • Pcf H — H- ^r HI to ro M C 0 to H- vO LO LO LO

•r- CO

4-» • 0 o rH HI ro rr LO

CO 2

CO CO cc 00 CO CO h- tx h- 0 x- r"- \ \ £S \ \ \ dTs o n

r-* HT 1 1-0 LO

— i ~ LO | LO LO o 1 o , o

Large

machine

used

is

instrument B

in

1978.
of the instrumental conditions employed, Table 9 is he

results of the analysis of the glass films measured by x-ray

fluorescence spectrometry. Some commercial thin films containing single elements were used as standards, including

previously measured thin sputtered films (e.g. F-20, F

2 5 )

It should also be noted that in the present instrument employed

a 12% oxygen, SS% argon atmosphere was maintained for sputtering the target, prior to deposition on the substrates for

at least two hours. For purposes of comparison the results

of previous work described in the July 1977 report (i.e.,

instrument A) are tabulated along with the results of this work

(i.e., instrument B) .

Comparison of the results in Table 10 indicate that the larger

instrument (3) used in 197S produced films whose composition

was closer to the bulk target composition for Ca, Zn, and Pb

The value for silicon is about the same for either instrument.

It is interesting to note that although preferential sputtering

for the light elements Si and Ca and a decrease for Zn and Pb

still exists, the absolute value of the relative difference

of all elements from the bulk composition is approximately the

same. From Table 9 it appears that varying the sputtering

parameters (voltage and ion-current) does not affect the film

composition appreciably . The best agreement was obtained in

sets 2 and 5 which were done in the same day under identical

conditions. Set 5 showed the largest deviation for Pb and

was prepared under the highest ion-beam current obtainable.

Even under these extreme conditions the Pb composition of set

5 was only 10-15 -j less than the average value of the other sets

These findings are important in that the ion acceleration voltage and ion-beam current principally determine the rate at

which the sputtered secondary atoms leave the surface of the

target with no significant change in the film composition.

t
TABLE 9

Composition of Glass Films Determined by

X-ray Fluorescence Spectrometry

Set No. % SiO ? % CaO % ZnO $ PbO

1 AV. 48.7 21.4 14.5 21.2

s 3

X

3.0 1.2 0.5 0.7

2 AV. 46.6 22.4 14.9 20.8

S x 1.0 0 . 5 0.3 0.5

3 AV. 46 .

4

21.7 14.7 20 . 5

S

X

1.1 0.4 0.3 0.4

4 AV. 43.5 22 .

4

14.2 18.4

S

X

0.9 0.5 0.3 0 .

3

5 AV. 4 5.6 23.8 13.3 16 .

7

S

X

0.2 0.1 0.1 0 .

1

6 AV. 47.5 25.4 15.4 19 .

5

S

X

0.6 0 .

3

0.2 0.2

Overall Average 46 .

4

22.9 14.5 19.5

S

° _AV

0.7 0.6 0.3 0.7

Bulk Comp 36.0 18.0 20.0 26.0

£ S^ is one standard deviation of the average value of each set

Vj S AV is one standard deviation o f the overall average of al 1

the sets

.

ID
o\°

o\°

TABLE 10

Comparison of the Average Composition of Sputtered

Films Using Two Different Instruments A and B

Instrument % SiO^

% CaO % ZnO

A, 1977

AV. 43.7 32 .

7.8

B, 1978

AV. 46.4 22 . 9 14.5

Bulk Comp. 36.0 18.0 20 . 0

% Re 1 . A,

a A + 21 + 78 - 61

% Rel . A,

a B + 29 + 27 --2 8

"Percent relative difference between the film and bulk

F i lm- Bulk

i . e

Bulk x 100.

PbO

8.8

19 . S 26 .

-66

-25

composition

,
Although there still exists an appreciable difference between

the target and the film composition, this is not . considered

important as long as the film composition obtained from any

particular target is constant and reproducible. The results

obtained thus far indicate that this is indeed the case. The

addition of oxygen in the sputtering atmosphere appears to

increase the content of ZnO and PbO in the films, and also

greatly decreases the amount of trapped argon in the films

.

Additional experiments are now in progress in which the amount

of oxygen in the sputtering atmosphere is being varied to quantitate its effect on the film composition.

Future Work

Further work is planned in 1979

targets of different elemental

and to prepare thin films from

is the fabrication of a target

borate matrix. The results of

next semi-annual report.

to fabricate additional glass

composition of interest to EPA

these. Of great interest to us

containing sulfur as sulfate in a this work will be reported in the
4 Particulate Physical and Chemical Characterization

4 . a . b . c Particle Doppler Shift Spectrometer (PDSS)

Progress has been made in the optical configuration, the

chamber design, and the data collection method. Calibration

of a commercial optical particle counter was performed. Also,

for the first time, experimental data reproducibly matches the

calculated Mie scattering curve features over a broad range of

sizes. These Mie features are reflected in relatively large

differences in the intensity of light scattered as a function

of particle diameter. This match of Mie features serves as an

internal standard to better than 0.2 pm accuracy for homogeneous,

spherical aerosol particles of four to .twenty urn diameter.

Before reviewing these advances, some comment on items in the

January 1978 and September 1978 Semi-annual Reports is in order.

First, methylene blue was found to be unsatisfactory for solid

size standard particles. The imaginary part of the index of

refraction was so large as to obliterate the Mie features. Second,

a vacuum system was implemented on the PDSS, and the predicted

increase in particle velocity was observed for 2 pm diameter

latex spheres. We have not yet pursued this further because of

difficulties in introducing the aerosol sample into the vacuum,

and because of a lack of Mie features for smaller particles

Third, computer matching Mie features to experimental data by

searching the index of refraction and density space has turned

out not to be practical. Index or density, but not both, can

be determined by matching the Mie features. We have found it

better to start with a substance of known index and density,

determined from the bulk material.

The new PDSS optical configuration increases the size resolution

and data rate by collecting light from a larger scattering volume

58
and from a more narrowly defined scattering angle. A viewing

microscope is included to give a visual check of the scattering

volume

.

The new chambers are designed to suppress convection and wall

interference effects as were present in previous chambers. The

new design also includes a Brewster window and a sample collection

surface (bottom window) that can be changed during a run.

An entirely new data collection scheme is being developed. The

spectrum analyzer collects the summation of many spectra in the

usual way for the Mie feature calibration. Simultaneously, the

computer accumulates the peaks (particles) by size, from each

spectrum, in real time. In this fashion, the size distribution

can be measured directly in terms of equivalent aerodynamic

diameter regardless of the shape of the aerosol particles. For

the case of homogeneous spheres made from well characterized

material, the equivalent aerodynamic diameter can then be related

to the optical diameter using the Mie feature calibration.

The match of Mie features mentioned above has been obtained with

a spray of pure di-octyl phthalate (DOP) from an atomizer. This

match is being used as a standard for investigation of DOP aerosol

generated by the following generators for which slight mismatches

are observed: the vibrating orifice generator, the atomizer at

higher flow rates, and aerosol spray cans. These mismatches may

be due to various effects which we can detect because of the

sensitivity of the Mie feature calibration technique.

Before the above match was obtained, a comparison of a commercial

optical particle -counter with the PDSS was performed at very

low particle concentration. The twelve particle sizes used

generated by the vibration orifice generator, were between four

and eight urn diameter. Results of this work are to be published.
4

d

e Development of Air Supported Pl a smas

No activity in this project during the last six months.

5 Particulates on Glass Fiber Filters

5.

a.i. I on -Chromatography

A recent acquisition to the Inorganic Analytical Research

Division of the Center for Analytical Chemistry at NBS is the

Ion - Chromatograph (Dionex Corp . , Sunnyvale, CA) . Acquired

in January 1978 and put into operation in March, the instrument

is now fully operational and has already been used to analyze

several diverse types of samples, ranging from oysters to air

filters

The Ion-Chromatograph is a new tool for trace analysis in

analytical chemistry that is based on the ion-exchange chromatographic separation of ionic species, followed by conductimetric

detections . The high background conductance associated with

the eluent is made negligible through use of a suppressor resin

column. The method is ideally suited for inorganic anions,

but is also applicable to low molecular weight organic acids,

as well as some cations and cationic species. Ion-chromatography

has already shown great promise toward the solution of complex

trace analysis problems, in particular, the speciation and

quantitation of species existing in, or are conducive to

conversion to, anionic forms. The potential of ion- chromatography

to determine several species simultaneously is especially attractive to the field of microanalysis. A typical analysis of a suitably prepared sample containing fluoride, acetate, chloride,

nitrite, phosphate, bromide, nitrate, sulfite, and sulfate, takes

about 25 minutes (Fig. 9). The minimum detection limit for these

common anions under standard conditions is about 0.5 ppm, with

a precision of 1 to 5 percent. The minimum detection limit can

40
I

ON

-CHROMATOGRAPHY

STANDARD

D

41
be extended 10 to 100-fold through use of larger sample loops

or concentrator columns. Current research indicates that, under

different chromatographic conditions, iodide can also.be determined with a minimum detection limit of about 0.2 ppm.

Since ion-chromatography is a chromatographic (separation)

technique, spcciation (c.g. sulfi.de/sulfite/sulfate; nitrite/

nitrate) is possible, and is primarily dependent on the method

of sample preparation. Aqueous samples, such as rain water,

fresh water, and sea water, may be analyzed with little or no

sample manipulation; solids must be solubilized, generally by

standard microchcmical techniques (dissolution, sonif ication

,

extraction, fusion, digestion, or combustion) . Such

manipulations may, of course, alter the rate of these species

in the original sample. Much research is being concentrated

in this laboratory in optimizing sample preparation methods

and chromatographic parameters for simultaneous multi-component

analyses in real samples.

The types of samples analyzed to date in this laboratory by

ion- chromatography include lyophilized oyster tissue, mechanical

packing products, glass fiber filters, penetrant inspection

materials, and waste oil.

The scope of the oyster project was to detect and quantitate

as many anionic species as possible in lyophilized oyster tissue.

It was intended to look at both the anions soluble in water, and

the anions resulting from a suitable combustion technique. For

the solubles, six peaks were detected, and identified by reference

to a standard solution. Quantitation was possible only to a very approximate level for the soluble anions (Table 11) (Figure

10) . Very good quantitative information on chloride and sulfur

was obtained after combustion of the oyster tissue in a Schoniger

oxygen flask (Table 12) (Fig. 11).
TABLE 11

Solubles in Oysters

Peak Identification and Approximate Quantitation

Peak

Probable Approximate

Species Concentration

a

b

c

d

e

Br

NO I

< 0 . 02 %

1 . 1 %

0.7%

<0 . 09%

<0.13%

f 0 . 19%
Figure 10. Solubles in oysters.

44
TABLE 12

Chloride and Sulfur (as Sulfate) Concentrations in

Oyster SRM as Determined by Ion- Chromatography

After Schoniger Flask Combustion

Sample Wt

.

Scrubber

Soln, Wt. Chloride Sulfa t

e

11.59 mg 20.10 g 1.034% 2.201%

24.36 20.07 1 .032 2 .259

19.80 20.00 1.057 2.244

12.05 19.99 1.010 2 .253

18 .32 19.99 1.037 2.258

17.33. 20 .20 1.051 2 .278

26.67 19.99 1.038 —

20.11 20 .02 1 .013 2 .300

Mean 1.034%

St d. Dev. 0.016 3

2 .256%

0.031

o\o

o\°
OYSTER

17.33 mg combusted in Schoniger flask

l mo r i a e and sulrur concentrations in ovs ter

determined by ion chromatography after Schoni

flask combustion.

(n

c

n
Leachable chlorides have been determined in mechanical packings

(Teflon asbestos or graphite- asbestos composites) at the 10-100

ppm level. Nitrate and sulfate on glass fiber filters were

determined for use as standards in air -part iculate analysis

(Table 13). Penetrant inspection materials used to detect faults

in steel welds were analyzed for fluoride and chloride in conjunction with an ASTM round-robin. These materials were combusted

in a ParT oxygen bomb prior to analysis. The level of chloride

in fourteen different samples ranged from 3 to 1800 ppm, and

fluoride from 0.5 to 200 ppm. Waste oil has also been analyzed

by ion- chromatography for chloride and bromide after digestion

by the sodium alcoholate method.

These five types of analyses briefly illustrate the types of

samples amenable to analysis by ion-chromatography. Obviously,

ion-chromatography has tremendous potential in the determination

of heretofore uncertified species in the NBS environment and

energy related Standard Reference Materials presently available

(such as coal and bovine liver) ; as well as in new materials

(such as the air-particulate filter strips) . It is anticipated

that the potential of the ion chromatograph will be fully exploited

in trace analysis application to such areas of activity at NBS.

4

"
TABLE 15

Summary Analysis of Filter Strips for Nitrate and Sulfate

by Ion-Chromatography

Nitrate Sulfate

Series Me an ( S ..D. ) (R.S.D.) Mean (S.D .) (R.S.D.)

II-BL 1.5 yg (1.0) 2 . 3 yg (1.5)

1 1 -A 100 .

yg (2.6) C 2 . 6 %

)

502.6 yg (8.9) (1.8%)

1 1 - B 1002 yg (16) (1.6%) 2002 yg (29) (1.5%)

II-C 2513 yg (43) (1.7%) 6939 yg (109) (1.6%)
S.a.ii Lead, Sulfate, and Nitrate on Filter Media

This SRM consists of Mo mm x 205 mm strips cut from glass

fiber filters. These filters are of the type commonly used

with high volume samplers for the measurement of atmospheric

particulates. Solutions containing known amounts of potassium

sulfate, potassium nitrate, and lead nitrate were prepared

gravimetrically and aliquots of 25 uL were pipeted onto the

filter strips. Four aliquots were transferred to each filter

in all cases except sample I-C which required five aliquots.

The pipets were calibrated by weighing similar aliquots transferred into weighing bottles.

The filters were prepared in a clean room and allowed to airdry before packaging in glassine envelopes. The filters

were prepared in groups of 100 and the proper number of aliquots

were dispensed into weighing bottles at the beginning and end

of each loading sequence, to monitor the performance of the

pipet

.

The values calculated from the composition of the solutions

and the quantities delivered by the pipets are in agreement

with the analytical values. The nominal values are shown in

the attached table 14. Six hundred filters at each level were

prepared

.

Work on Pb on GFF has started and is being steered toward

development of an SRM.

Work on sulfate and nitrate also being steered toward development of SRMs

.

4 9
TABLE 14

Nominal Values of SO^

,

NO- , and Pb

- ug/filter

on Filters

Filter Group Sulfate Nitrate Lead

Blank 0 0

I -A 500 100

I - B 2000 1000 - - I-C 7000 2500 - -

Blank — 0

1 1 -A 100

1 1 - B 500

II-C 1500

6 Urban Air Particulate Was hington D. C. Sample

Work begun under this task to be reported on in next semiannual report.

7 Develop SRMs for Coal Conversion Processes and Materials

Balance Determinations

A multi -element radioanalytical procedure for the simultaneous

determination of As, Cr, Se, Sb , Cd, and Cu was developed and

applied to two NBS environmental standards, a new Fly Ash SRM

(1655a) and a new Sub -b ituminous Coal SRM (1655). An inorganic

ion exchanger coupled to a solvent extraction system was used

for the selective separation of these elements from neutronactivated matrices. The results are shown in Tables 15 and 16.

During dissolution of the Fly Ash SRM, large losses of chromium

were observed. These losses were mainly due to the large amounts

or HF needed ror complete dissolution of the highly silaceous

matrix and the fact that chromyl fluoride is extremely volatile.

5 0
Because of the losses of chromium, instrumental neutron activation analysis was used to analyze chromium in the Fly Ash.

TABLE 15

NBS SRM Sub -bi tuminous Coal (1655)

Element Certified Values a This Work 3

As 0.42 ± 0.15 0.44 + 0.05

Sb (0.14) 0.12 ± 0.01

Se 0.9 ± 0.3 0.82 ± 0.04

Cr 2.5 ± 0.3 2.48 4- 0 .08

Cd. 0 .03 ± 0.01 0.029 ± 0.005

Cu 3.6 ± 0.3 3 . 56 ± 0.18

TABLE 16

NBS SRM Fly Ash (1653a)

Element This Work3

As

b 146 ± 6

As 152 ± 8

Sb 6 .07 Hr .61

Se 11 ± 1

Cr

b 200 ± 7

Cd 1 . 06 + .16

Cu 121 ± 6

£ Units in ug/g.

Determined by Instrumental Neutron Activation Analysis.
s Development of an Oil Shale SRM

A preliminary analysis of the proposed Oil Shale SRM has been

done by instrumental neutron activation analysis (INAA) for

elements having intermediate and long-lived neutron irradiation

products. The observed elemental concentrations are listed in

Table 17, along with the estimated uncertainties obtainable by

INAA. The concentrations of approximately thirty elements can

be determined by INAA. In general, the concentrations of trace

elements in the Oil Shale is very similar to those in SRM 1652a

(Coal)

Arrangements are being made to have some of the Oil Shale

sterilized. This sterilized material will be compared to some

unsterilized Oil Shale to determine if there are any changes in

the elemental concentrations of volatile elements. Some of

the sterilized and unsterilized material will be given to the

Organic Analytical Research Division to look for differences

in the concentrations of organic compounds.

D -
TABLE 17

Approximate Elemental Concentrations in Shale Oil

as Determined by INAA

y g/g Estimated Uncertainty (°Q

Na 1 . 6 a <5

K 1.0 a <5

Rb 63 <5

Cs 3.4 <5

Ba 540 5-10

Sc 4.6 <5

Cr 32 <5

Fe 1 . 8 a <5

Co 9.0 <5

As 64 <5

Se 3.5 5-10

Sb 2.8 5-10

La 20 <5

Ce 34 <5

Sm 2 . 5 <5

Eu 0.52 <5

Yb 0 .85 <5

Lu 0.18 <5

Hf 1.5 5-10

Ta 0.30 10-15

Th 4.7 <5

Value is given as percent, all other values are in ug/g.
' S. Department .">1 i\immerce Joanna M. Kreps

^ecretarv

National hurruu oi -tanilartl' V.rrcM Aint'.rr Oiteetor ^aiimial pursaii: of jSiamiartis

(Igrimtais of JKnalosts

Standard Reference Material 1648

Urban Particulate Matter

This Standard Reference Material is intended for use in the calibration of methods used in the chemical analysis

of atmospheric particulate matter and materials with similar matrices. The material is atmospheric particulate matter collected in an urban location.

The certified values are based on measurements of 6 to 30 samples by each of the analytical techniques indicated.

The estimated uncertainties include those due to sample variation, possible methodology differences, and errors of measurement (see Preparation and Analysis). The certified values are based on a sample size of at least 100 mg of the dried material. The material should be dried at 105 °C for 8 hours before use.

Element Mg/g Element Weight %

Arsenic'

c 115 ± 10

t a b c e Iron 3.91 ±0.10

~ . abed Cadmium 75 ± 7

. ,abd Lead 0.655 ± .008 Chromium6 c 403 ± 12 o — a b e Copper

Nickel

3 bd

_. abed

Zinc

Uranium6

609 ± 27

82 ± 3 4760 ± 140

5.5 ± 0.1

Atomic Absorption Spectrophotometry

isotope Dilution Mass Spectrometry Neutron Activation Analysis

Polarography

Spectrophotometry

The overall direction and coordination of the technical measurements leading to certification were performed

under the chairmanship of J.'K. Taylor.

The technical and support aspects involved in preparation, certification, and issuance of this Standard Refer- ence Material were coordinated through the Office of Standard Reference Materials by W. P. Reed.

Washington. D.C. 20234 j. Paul Cali, Chief

November 16, 19/8 Office of Standard Reference Materials

(over)

54
Preparation and Analysts

litis SRM was prepared from urban particulate matter collected in the St. Louis, Missouri, area in a baghouse

especially designed for this purpose. The material was collected) over a period in excess of 1 2 months and, therefore, is a tiinc^integrated sample. While not represented to be typical of the area in which it was collected, it is believed to typify the analytical problems of atmospheric samples obtained from industrialized urban areas. The material was removed from the filter bags by a specially designed vacuum cleaner and combined into a

single lot. This product was screened through a fine-mesh sieve to remove most of the fibers and other

extraneous material from the bags. The sieved material was then thoroughly mixed in a V-blender, bottled, and

sequentially numbered.

Randomly selected bottles were used for the analytical measurements. Each analyst examined at least 6 bottles, some of them measuring replicate samples from each bottle. No correlation was found between measured

values and the bottling sequence. Also, the results of measurements of samples from different bottles were not

significantly different than the measurements of replicate samples from single bottles. Accordingly, it is believed that all bottles of this SRM have the same composition.

The analytical methods employed v/ere those in regular use at NBS for certification of Standard Reference

Materials, except as noted in the following paragraphs. Measurements and calibrations were made to reduce

random and systematic errors to no more than one percent, relative. The uncertainties of the certified values

listed in the table include those associated both with measurement and material variability. They represent the

95 percent tolerance limits for an individual sub-sample, i.e., 95 percent of the sub-samples from a single unit of

this SRM would be expected to have a composition within the indicated range of values 95 percent of the time.' The following values have not been certified because either they were not based on results of a reference

method, or were not determined by two or more independent methods. They are included for information only.

All values are in units of pg/g of sample, unless otherwise indicated.

Aluminum (3.3 wt. %) Lanthanum (42)

Antimony (45) Magnesium (0.8 wt.%)

Barium (737) Manganese (860)

Bromine (500) Potassium (1.0 wt.%)

Cerium (55) Samarium (4-4)

Cesium (3) Scandium (7) Chlorine (0.45 wt %) Selenium (24)

Cobalt (18) Silver (6) Europium (0.8) Sodium (0.40 wt %)

Hafnium (4.4) Thorium (7.4)

Indium (l.0)i Titanium (0.40 wt. %)

Iodine (20)' Tungsten (4.8)

Vanadium (130)

55
The values listed below are based on measurements made in a single laboratory, and are given for information

only. While no reason exists to suspect systematic bias in these numbers, no attempt was made to evaluate such

bias attributable to either the method or the laboratory. The method used for each set of measurements is also

listed. The uncertainties indicated are two times the standard deviation of the mean.

Nitrogen (NO3 ) Nitrogen (NH4 ) Sulfate

Si02 Freon Soluble

(1.07% + 0.06)

(2.01% ± .08) (15.42% ± .14)

(26.8% ± .38)

(1.19% ± .47)

The above values were determined by the methods indicated below:

Nitrate • Extraction with water and measurement by ASTM Method D992.

Ammonia — NaOH addition followed by steam distillation and titration.

Sulfate ~ Extraction with water and measurement by ASTM D516.

Si02 Solution and measurement by ASTM Method E350.

Freon Soluble — Extraction with Freon 113, using the method described in “Standard

Methods in Examination of Water and Waste Water," 14th Edition, p. 518,

American Public Health Association, Washington, D.C.

J. W. Matwey supervised the collection of the material as well as sieving and bottling. The following members

of the staff of the N BS Center for Analytical Chemistry' performed the certification measurements: R. W. Burke:

E. R. Deardorff; B. I. Diamondstone; L. P. Dunstan; M. S. Epstein; M. Gallorini; E. L. Garner, J. W. Gramlich:

R. R. Greenberg; L. A. Machlan; E. J. Maienthal; and T. J. Murphy.
80 -BCL-b- ENERGY RELATED AIR POLLUTANT ANALYSIS INSTRUMENTATION

1 Development of an instrument to measur e a i r b o rne s u 1 fate

particulate matter

Introduction

Thi s progress report pres ents th e r esul ts of further study of the

pul sed flame photome trie sulfur ana ly zer and of the effects of SO

and humidity on the calib ration of the sy stem w ith (NH^) ? S0^ and

H ? SO. aerosols. The syst em has bee n used in a mobile laboratory

by the University of Minn esota i n r ecent field studies and field

cal. ibration results will be comp are d with those obtained from

laboratory calibration.

Calibration Results

The laboratory calibration technique consists of generation of an

ammonium sulfate or sulfuric acid aerosol by atomization of the

appropriate solution, followed by dilution with dry air and neutralization of the aerosol with a radioactive neutralizer. The

humidity of the sample is adjusted by mixing with the required

amount of moist air to give the desired relative humidity. Part

of the sample is fed to the pulsed FPD system and part to an EAA

(electrical aerosol analyzer) to determine the sample concentration.

Figure 12 shows the pulsed FPD system response to ammonium sulfate

aerosols at various relative humidities with and without SO ? added to the sample. Figures 13 and 14 show the response of the

pulsed FPD system in mV output versus sample sulfur concentration

in ygS/m J for ammonium su

Calibrations were done at

high humidification (v60r

The results in all figure

systematic dependence of

If at e and sulfuri c a cid , respectively • low humid if icati on ("-10 r . h . ) and at

.h.) with SO. lev els 0 f 0 ppb and 'vlO ppb

s show considerab le scat ter as well a s a the results on bo th SO. and relative

o
rc4

c\r\i

CM

£5

*Q

0Z,

». 4

ires v s *->0 \_y

w

CLCL O

C 0

L •* CL -P CL U

0 L

_n

% vl

*13 r-J o a

“U o cju OUT)

CO **<

c* t n

_0 Q

' ^

V Si

I

(V

W

cv

w

I\J

(S3 0S

+ r?*»

i L y

n

cr

i—i—i—

m

cm

-t—-p H f h

a

CM

r AU- M/q ti \ £t I t V/

lD

H iL> V» fcV W V*\ vJ

li $

figure

12.

Pulsed

PPD

system

response

to

ammonium

sulfate

aerosols

at

various

relative

humidities

with

and

without

S0

?

added

to

the

sample.

CG

CO

'•1 s /0

St Jj) 0L0

•H VI £

01S c0

•H

4->OL

+>C00c0uLD

Q-

~D

tTN u

Jj ^ b £ 0

r-Hau

G 6 0 0)

CO

to3

tou • a> -r-U

4-» 3 3

3.O

+J -rH 3 3 O 3

t> < 2 3

to 3~ <T-I O

4_)m

to c/3

CO

a

to 3

rH

C 3 >H

3. 3 o 3G

'-3 o O 3O

03U

to3 3 C 3 O 3 O

CO
results in Figure 12 show ingo ins t rumen t s ens i

- mV) as a fun ction of relative humidity are quite

the p resence of a,lOppb added S0 o , but s how great

S0 9 is present.

In the figures a field calibration value is also indicated. This

was obtained from a comparison of the average response of the

sulfur monitor and x-ray fluorescence analysis of filter samples

taken during the corresponding averaging time interval. This

3 comparison gives a value of 3.45 ygS/m mV for the pulsed FPD

instrument response. This is plotted in the figures and one can

see that in the cases where the sample is humidified (v60% r.h.)

and where SC^ is present (vlOppb) the agreement with laboratory

calibration results is quite good. This is encouraging because

the field results were obtained under conditions similar to these

We are still not able to explain the results for low relative

humidity and S0 ?

. Low S0 9 may accentuate some noise problems with

the nonlinear amplifier' in the ' FPD and signals around zero may

cause problems in signal averaging by the lock-in amplifier. We

are also going to check the use of the EAA as a means of characterizing the calibration samples by comparing it with values

obtained by filter and QCMM (quartz crystal mass monitor)

measurements

.

Conclusion

The pulsed-FPD sulfur analysis sytem has performed well in field

study applications and the results obtained are in agreement with

results obtained by other techniques. Several problems still

exist related to the effect of relative humidity and gas phase

sulfur on calibration techniques. We must determine if these

effects are related to the system response or our calibration

methods. Field and laboratory calibration values are consistent

and in agreement for laboratory calibrations done under conditions

similar to those in the field study.

61
SO -BCL-c -ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

1 Radiocarbon as an Environmental Tracer

Introduction

The first results demonstrating the feasibility of mini-low level

counting (lie) of radiocarbon to distinguish anthropogenic from

natural pollutant sources, using only mg sample sizes, have been

published (1,2). Following this accomplishment, we have taken

steps to further extend our capabilities — in terms of sample

size, throughput, and quality control. We have undertaken cooperative experiments at the request of the Oregon Graduate Center and

the University of Washington to apply our unique method to two

specific environmental problems. These particular applications

served also as a logical next step in our research, for they

allowed us to increase the discriminating power of the (lie) method

through the addition of chemical and physical (particle size)

selectivity

Building on the experience of the past year, we are now developing

future directions to make major advances in our capabilities

through the use of accelerator mass spectrometry ( AMS ) , large lowbackground proportional counters, stable isotope analysis, and

trace gas radiocarbon analysis (Ref. 3 and App . III). These

approaches will make possible far more selective and reliable

information on source strengths, residence times and transport

mechanisms of carbonaceous species in the environment; and the

resultant data could provide important insight concerning

paleopollution and the influence of atmospheric species on climate.

Parallel activities directed toward measurement accuracy and model

validity have also taken place. A comprehensive treatment of the

question of accuracy in chemical analysis has just been published

6 :
1(-1), and a robust (assumption-resistant) approach to spectroscopic peak resolution will shortly appear (Append ix Tl)(5). This

latter publication lias important implications for the reliable

extraction of pure component signals from overlapping peaks in

chromatograms and X- and y _ra y spectra. An evaluation has just

begun of high precision radiocarbon data from an international

intercomparison involving 17 competent radiocarbon dating laboratories (this evaluation is indirectly related to the issuance of

a new standard)

.

Quality Control and Measurement System Developments

As atmospheric species of interest exist at very low concentrations, we are attempting to a) improve our analytical technique by

lowering detection limits to meet small sample size requirements

(yg to mg) , b) increase measurement precision for optimum source

discrimination, and c) expand our multiple capability for increased

throughput. For samples at the 5-10 mg carbon level, we are

currently striving to improve (lie) precision from the existing 10

percent to 1-3 percent*, by assuring an adequate level of quality

control and by improving counter design. Through 3 counting of

natural radiocarbon is only practical for as little as 1 mg of

carbon (restricted by Poisson Statistics) , the accelerator

technique ( AMS ) for carbon-14 counting holds the only prospect of

reaching the yg level for environmental and dating problems with

good precision. Because of the complementary nature of the two

approaches, we are currently investigating both.

*ln Kef. 2 [Eq. 1,2] we showed that a relative standard deviation

of three percent could be achieved in principle, simply by

extending our counting period to one week.

63
Quality control for the exist ini1

, (lie) system (at the 5-10 mg carbon

level) is presently taking place through the replication of background and standard measurements. Background measurements which

arc monitored between sample and standard counts, utilize CC^

from dry ice, P10 (90o Ar and 10* CH

4

) , and CH

4

, all of which are

derived from natural gas. Also used is a blank standard, subbituminous coal - SRM 1635. Table 18 summarized background

measurements for newly constructed 5 and 15 mL counters.

TABLE 18

Counter

(nominal

volume)

(5 mL)

Counter Backgrounds

Counting Gas

CH^ - 3.7 atm

CO

2

- 3.9 atm

CO

2

- 2.8 atm

Source

Natural Gas

Natural Gas

Sub-bituminous Coal

- SRM 1632a

Count Rate a (cpm)

0.081 ± 0.008

0.093 ± 0.009

0.087 ± 0.005

J

c CC>2 - 4.2 atm Natural Gas 0.094 ± 0.004

(5 mL)

M

c CC>2 - 1.0 atm Natural Gas 0.132 ± 0.008

(15 mL)

‘Uncertainties represent Poisson standard deviations.

‘External iron shielding.

^External lead shielding.

64
Beyond the limit of our shielding, i.e., thick i on or lead

external shielding plus pure copper internal shielding, the background rate is limited by counter site and construction material

purity. In order to minimize these effects, counters have been

constructed of high purity quartz, and volume has been reduced

such that elevated pressures are required to assure sufficient

sample activity. These experiments have been successful in that

routine operation ut> to several atmospheres is not possible, with

no detectable pressure dependence of the background rate. The

international radiocarbon dating standard (Oxalic Acid, SRM 4990B)

has been used for counter calibration, and this and two other

reference samples have been used for quality control or interlaboratory comparison of percent contemporary carbon activity

of environmental samples. The follo^.ving materials are used in

our laboratory: NBS contemporary oxalic acid, SRM 4990B; USGS

wood sample (7060 ± 250 yrs. B.P.); and urban dust air

NBS SRM 1648 (Table 19) .

S' V V

The results in Table 13 thus illustrate three phases or our work

calibration (NBS-Oxalic Acid SRM- standard) , measurement (urban

dust SRM) , and quality control (USGS wood sample) . The result

for the USGS wood (counter N) is consistent with the known age,

and the result for the urban dust is the first quantitative

radiocarbon assay of that material.

Quality control for (lie) is monitored by a continuous record

anticoincident count rate, meson rate, and guard rate. Pigur

is an illustration representing ca

USGS wood samole. The

:a crcm :r measurements W 11 s rameters monitored (Rr , R. , R.~) rerr

u _ .-vL, us to assess electronic and counter s tab Hit'

efficiency, and counting gas purity. A fourth parameter, bare

metric pressure, will be added for high precision measurements

evaluation of trends in guard and meson rates. For the initia.

observations (1-4) in figure 15, neither precision r.cr control
Observed

Fraction

of

Contemporary

(1878)

Carbon A

I

BCD

I \ t

Expected Fraction of Contemporary Carbon

(Pure Source)

Figure IS. Anticoincident (R^,) , meson (R

y ), and guard -(R.) count

rates (cpm) versus run number for US GS Wood Sample utilizing Counter J. Poisson uncertainties (±lj) are

represented by error bars for corresponding point

s vmb o 1 s .
TABLE 19

Standards and Reference Samples

Counter Percent

(nominal Counting Standard and Net Count Rate Modern,

volume) Gas Reference Samples (cpm/ 10 mg C) Carbon

N C0~ NBS - Oxalic Acid 0.090 + 0.005 105%

L SRM 4990B

USGS Wood Sample

(7060 ± 250 yr B.P.)

0.029 -+* 0.005 34%

NBS - Urban Dust 0.048 + 0 . 006 56%

SRM 1648

J C0 o NBS - Oxalic Acid 0 . 097 + 0.007 10 5%

(5 mL)

L SRM 49 9 0B

USGS Wood Sample

(7060 ± 250 yr B.P.)

0.038 + 0.004 41%

M C0 ? NBS - Oxalic Acid 0.085 + 0.009 105%

(15 mL)

Uncertainties represent Poisson standard deviations.

Percent modern carbon = Net Sample Activity

0.95 x MBS Oxalic Acid SRM x 10 0%

were adequate, due in part to insufficient counting time and

external difficulties (air conditioning and computer shutdown)

.

For the rest of the sequence, all observations are consistent

with counting statistics, except for small barometric pressure

related variations in R r and R .

A planned expansion of our multiple counter capability is underway (—first) through the investigation of source (s) of spurious

pulses. Our present system, which uses two-dimensional spectrometry, (energy v_s rise time), is limited to the simultaneous

0
operation of four counting channels. If sources of spurious

pulses can be identified and controlled, then counting can be

accomplished by energy discrimination only. It would be then

much more practicable to utilize the full capacity of our present

shielding, which can accommodate 50 to 100 counters. A Cromemco

1-2 Computer System, with an 8-inch dual floppy-disc drive, line

printer, viewing screen, and teletype will be installed shortly

(J. R. DeVoe, personal communication) for acquisition and reduction of radiocarbon data. With this new system environmental

parameters influencing count rate, such as barometric pressure,

room temperature, and humidity, as well as the previously discussed

counter-control parameters, can be continuously monitored.

Applications to Pollutant Source Identification

During the past three months experiments have been completed to

access the applicability of radiocarbon measurements (lla) to

resolve the contributions of field *and slash burning, wood stoves,

natural emissions, fossil fuel combustion, etc. to the total

urban particle load in areas such as Portland and Eugene, Oregon

(6). This cooperative project with Prof. John A. Cooper of the

Oregon Graduate Center (OGC) complements an extensive analytical

program at OGC to determine the maior sources of airborne

carbonaceous and non-carbonaceous particles. From the many

particulate samples taken in the Portland area at different

locations, and for differing collecting periods, meteorological

conditions, and particle size fractions, a select group (filters

71-8, see Table 20) was taken for radiocarbon assay as most

representative of the sources in question. Radiocarbon results

will later be compared to the results of inorganic analyses to

develop a powerful tool to derive quantitative information on

sources of fine particles as an aid in defining sources on days

when air quality criteria are exceeded.
TABLE, 2 0

Modern Carbon in Portland Aerosols

Carbon

Filter

Number

Collection

Date

Primary

Impact

Size

Fraction

Mass

(mg)

Percent

Contemporary

1 18 Oct

.

77 Slash Total 48 47 + 12

2 Fine 11 107 + 18

*T0 F ine 21 80 ± 15

4 23 Jan

.

78 Fireplace Fine 24 62 a. 13

5 Total 72 45 + 12

6 17 Aug. 77 Violation

(No Burning)

Total 22 77 + 15

7 11 Aug. 78 Field Fine 42 107 ± 15

8 3 Aug

.

78 Slash Fine 29 76 ± 12

Total 72 104 4. 16

As with our previous study (1) , the Oregon aerosol project

utilized radiocarbon (lie) for source discrimination. Two new

elements are added, however: a) not all of the Oregon sources

can be distinguished with ^C (vegetation contains modern carbon)

,

and b) selectivity was enhanced through the measurement of radiocarbon in size-fractionated material. Further discussion of

these matters will be found in References 3 and 6; and a visual

summary is given in figure 16, which shows that the radiocarbon

content of the fine particle fraction is a reliable indicator for

sources such as field, slash, and fireplaces.

A second cooperative study (with J. Swanson, Univ. Washington)

relates to the organic fraction in marine sediments, which is

derived primarily from planktonic matter. Of this fraction, the
(lAIdOpy

UAldO)

K

y

UA!dO)

0

o

<

cc 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Run Number

Figure 16. Comparison of observed with expected vegetative impact

(fine particles). Dashed line represents the idealized situation for a pure source. The numbered box

(

; 5 j

)

indicates the median result; and the individual

result uncertainty (rlc) is shown for sample -4 only,

for clarity. Abscissa locations (A,B,C,D) are derived

from the atmospheric radiocarbon input function and

the mean ages (t) of the material burned. A (fossil

:ue (slash,

C (fireplac: at core

at core v 200 vrs . )

yrs.), D (field, t v 0)

"0
lipid component constitutes 20 to 50 percent, and 5 to 20 percent

of this is in the form of fatty acids with the remainder being

hydrocarbons. Polycyclic aromatic hydrocarbons (PAH) , known to

include carcinogens, have been extracted from the lipid fraction.

Since there is some question as to whether a natural marine

source for PAI1 exists, it was suggested (Swanson, personal communication) that measurement of the radiocarbon content of the

aromatic and fatty acid fractions could help identify the source.

Presently there are contradictory opinions as to the major source

of PAH found in marine sediments. Blumer et al., (7), have

investigated the molecular weight distribution of the PAH in marine

sediments from Buzzards Bay, Massachusetts. They found the

unsubstituted hydrocarbons predominate and suggest that (natural)

forest fires form, and that air currents disperse, a complex PAH

assemblage that eventually accumulates in soils and recent

sediments.

On the other hand, Hites et al. (8), found a correlation between

the time distribution of alkyl homologs of PAH in sediment, and

the timed distribution calculated for coal, wood, oil, hydroelectric, and gas combustion-product PAH. The authors specifically

suggested that fossil fuel combustion is the primary source of

PAH in recent (1850-present) Buzzard Bay, Massachusetts marine

sediments. The objective of our cooperative project with Swanson

will therefore be to test the hypotheses that the PAH fraction is

primarily natural or anthropogenic in origin. Our (lie) system is

required because it is quite impractical to get more than 10-20

mg of aromatic hydrocarbons from large amounts of sediment.

A third environmental matter to which we are now giving major

attention is the question of the relative amounts of atmospheric

Cli^ , CO, and light hydrocarbons that are generated by man compared

to that from natural sources. Previous investigations (9,10) of

the radiocarbon in atmospheric CIl ^ showed the average contemporary

carbon content as 80 percent, indicating that four-fifths of the

71
CH, was of recent biological origin. Atmospheric carbon monoxide

was also investigated ;il), and found to be “5 percent contemporarv

carbon. These data are questionable, however, since the samples

were provided bv air- licuef ication plants situated in industrial

areas. Our current plans therefore call tor remeasuring L m

these gases in contamination- free regions using portable sampling

apparatus

References

1. Currie, L. A., Kunen, S. M. , Voorhees, K. J., Murphy, R. 3.,

and Koch, W. F., Conference in Carbonaceous Particles in

the Atmosphere (197S) . 2. Currie, L. A., "Environmental Radiocarbon Measurements,"

Proceedings of the First Conference on Radiocarbon Dating

with Accelerators , University of Rochester, 19”S, p. 572.

5. Currie, L. A. and Klouda, G. A., Advances in the Discrimina - tion of Natural from Anthropc . enic Carbonaceous Pollutants

via Isotopes of Carbon , presented before the Division of

Environmental Chemistry, American Chemical Society, (April,

1979) . 4. Currie, L. A., "Sources of Error and the Approach to Accuracy

in Analytical Chemistry," Chap. 4 in Part I, Vol. I, Treatise

on Analytical Chemistry , I. M. Kolthoff and ?. Elving (Eds.),

John Wiley § Sons, Inc., New York (1978).

5. Ritter, G. L. and Currie, L. A., "Resolution of Spectral

Peaks : Use of Empirical Peak Shape," Proc. Conf. Computers

in .Activation Analysis and Gamma-Rav Spectrosconv , Amer.

Nucl . Soc . (1979) . 6. Cooper, J. A., Currie, L. A., and Klouda, G. A., "Impact of

Vegetative Burning on Urban Air Quality as Defined by

Carbon- 14 Measurements," to be submitted to Environ. Sci.
7

. Bluraer, M. and Youngblood, W. W., "Polycyclic Aromatic

Hydrocarbons in Soils and Recent Sediments,” Science 133 , pp. 53-55 (1975).

S. Hites, R. A., LaFlamme, R. E., and Farrington, J. W. , "Sedimentary Polycyclic Aromatic Hydrocarbons: The

Historical Record," Science 193 , pp . 829 (I9~7)

9.

Libby, W. F., Personal Communication (1978).

10. 3ainbridge, A. E., Suess, H. E., and Friedman, Irving,

"Isotopic Composition of Atmospheric Hydrogen and Methane,"

Nature, pp. 648 (1961).

11. MacKay, C., Pandow, M. , and Wolfgang, R. , "On the Chemistry

of Natural Radiocarbon," J. of Geophys . Res., 68 , pp. 5929 (1965).

12. Swanson, J., Personal Communication.
Appendix 1

Resolution of Spe

G. L. Ritter and

National Bureau o

ctral Peaks

Use of Emp irical Peak

L. A. Currie

f Standards, Washington

D. C.

Shape"

ABSTRACT

A semiempirical method of gamma- spectrum peak resolution (PICO)

which uses experimentally determined singlet peak shapes, has

been devised to minimize sensitivity to systematic deviations

from assumed analytic shape functions. The resolving power and

accuracy of the method have been demonstrated through the use of

International Atomic Energy Agency test spectra having Poisson

measurement precision of about 0.5 percent and peak separations

ranging from approximately 0.3 to 1.3 full width at half maximum.

* Proc. Conference of Computers in Neutron Activation Analysis and

Gamma -Ray Spectroscopy (American Nuclear Society, in press).
Mot For Publicatio n Presented Before the Bivision of Environmental Chemistry

American Chemical Society

Honolulu; April, 1979

ADVANCES IN THE DISCRIMINATION OF NATURAL FROM ANTHROPOGENIC

CARBONACEOUS POLLUTANTS VIA ISOTOPES OF CARBON

L. A. Currie and G. A. Klouda

National Bureau of Standards, Washington, D. C. 20234

Introduction

Alteration of the natural radiocarbon concentration in

living matter by the dilution of atmospheric carbon dioxide with

fossil ("dead") carbon was first recognized by Suess (1) through

the examination of the 14 C/ 12 C ratio in early twentieth century

tree rings. This dilution effect was subsequently employed by

Clayton et.al. (2) and Lodge et.al. (3) to estimate the anthropogenic

(fossil carbon) contribution to carbonaceous atmospheric particulates in urban locales. Although the potential of this method for

determining the impact of man's use of fossil fuels on the current

and historical burdens of carbonaceous pollutants was clear, its

application was severely limited by the large samoles required -- typically grams of carbon — for measurement with conventional

radiocarbon dating facilities. The possibility of overcoming the

foregoing limitation through the use of miniature, high-purity,

low-level counters was investigated two years ago (4); and the

first measurements on milligram amounts of carbon from air particulate samples were reported earlier this year (5)

Measurement Techniques; Results

Two approaches currently exist for the assay of the radiocarbon

content of atmospheric carbonaceous gases and particles, using

small (~ng) carbon samples: mini-low level counting { lie ) and

Accelerator Mass Spectrometry {.AMS ) . Both methods are appropriate

for the resolution of fossil from biogenic carbon in environmental

pollutants. The advantage of lie is that it is already developed

for routine use and it requires somewhat less expensive facilities;

AMS has the potential for greater throughput and improved precision.

A comparison of the Poisson precision of the two methods applied

to environmental samples is given in the proceedings of the first

Conference on the new accelerator technique (6)

Recent developments in our lie method, involving multiple counting channels

and improved detector design, give us the possibility of achieving

adequate pollutant source discrimination with a throughput of about

one result every three hours (lOmq - C).
The aDoroach is currently being applied to milligram

samoles of atmcsoheric gases (CH 4 , CO), urban and rural particulate

material , and na-ural and pollutant organic species in marine sediment (7). Details of the sampling, preparation of high purity C0 2

counting gas, and special countina techniques have been given in

Ref. 5. Requisite counting sensitivity was achieved through the

design of small volume (5-15 mL) hiah purity quartz proportional

counters with minimal dead volume, and through the combination of pulse

energy and pulse shape analysis to discriminate against radioactive

contaminants and electronic noise. These measures led originally to

a net signal from 10 mg of contemporary carbon which was comparable

to the backround rate, both being about 0.1 cpm. As a resu_t, an

adequate level of (Poisson) precision could be achieved with about a

one day count. Results of l Ic applied to urban and desert samples (5)

showed" over 70 percent fossil carbon in the urban samples

,

. but

little if any in the desert sample. The smallest sample size in the

set consisted of just 5.3 mg-C; this sample, collected in Salt bake

City, yielded a result of 72 + 13 percent fossil carbon in 2 . 7 days of

counting time.

Future Directions: Chemical and Isotonic SelectivityThe dichotomous "dead or alive" hypothesis for distinguishing

anthropogenic from natural carbonaceous pollutants is too simple.

Though useful when the two source components are chemically stable

and strictly correlated with fossil and biogenic [living) carbon, the

hypothesis breaks down in certain cases involving contaminable/unstable sample species or when non-fossil carbon is released through

man's activities (or the converse). Fossil carbon, for example, can

be released through natural volcanic or geothermal activity; and

biogenic carbon can be released through man's burning of wood,

fields, etc. Similarly, radiocarbon itself arises from both

natural (cosmic ray interactions) and anthropogenic (nuclear tests,

reactors, tracer experiments) sources.

In order to achieve reliable conclusions with such, a multiplicity

of sources, we can: (a) employ carefully-designed sampling plans,

(b) augment the radiocarbon measurements through the selection of

critical particle sizes and chemical species, and (c) add a second

dimension to our isotopic space through the measurement of 13(3.

The first two approaches have already been implemented (7), and the

third is under investigation. Typical of the sample selection referred to is the separation of size fractions for the removal of

large biogenic particles (spores, etc.), and the measurement of

radiocarbon in individual chemical fractions such as "soot", and

aliphatic and aromatic hydrocarbons.

6
Table 1

ISOTOPIC SOURCE INDICATORS

14 C (%) (a) 13 C (%) (b)

Concentration Variation Concentration Variation

artificial 14 C

biosphere

>> 100 . ~ 130 .

unpredictable

injection^

dispersion

PDB (CO 3

) C0 2 (atm)

0 . -0.7 si. season

al, local

effects

cosmic rays 100 . solar,

geomagnetic

field

C 4 plants

(grasses ) -to

to

-UB

species

local

climate

decay t =* 8270 yr. C 3 plants

(trees)

,

coal

,

petroleum

- 2.2 to

-12

species

,

local

climate

precursors

fossil fuel 0 . Natural gas -15

to

-4J3

species

,

precursors

Dry ice -52

(a) Standard (100%) is 0.95 x for causes and magnitudes

NBS oxalic acid SRM. See re of variation.

ferences 8 and 10 ,

(b) Standard (0%) is Peedee Belemnite. (Conventional units are . ) See

reference 9 for information on standard and variations.

By complementing the radioisotope (^C) measurements with

information on the stable isotopic (13<~) composition, we have the

possibility of increased source resolving power. As shown in Table 1,

the ability to resolve fossil carbon from most living plants lies

with -*- 4 C, whereas provides the means to resolve certain classes

of fossil fuels as well as certain classes of living matter (C 3 from

C 4 plants). Two important conclusions regarding the use of the

carbon isotopes are apparent from the table: (a) careful attention

must be paid to the causes and ranges of intraclass variations, and

(b) the concentration differences between (resolvable) sources imply

the requisite measurement accuracy. That is, an uncertainty of

about 10 % is adequate for hut as little as 0 . 1 % is required

for 33^ measurements.

In conclusion, a brief survey will be given of some environmental

problems which may be attacked with the new approaches. These include

the identification of fossil, natural and nuclear (cower., testing)

sources of atmospheric carbon; the assay of pathways and residence

times for atmospheric carbonaceous species; and the investigation of

the historical record of carbonaceous sources via analysis of

material from ice cores and sediment.
REFERENCES

^Suess, H. E., Science, 122 , 415 (1955).

2 Clayton, G. D., Arnold, J. R. , and. Patty, F. A., Science,

122, 751 ' (1955)

3 Lodge, J. P., Jr, Bien, G- S., and Suess, H. E., International Journal of Air Pollution, 2_, 309 (1960) .

^Currie, L. A., Noakes, J. , and Breiter , D. , "Measurement

of Small Radiocarbon Samples: Power of Alternative Methods for

Tracing Atmospheric Hydrocarbons", Ninth International Radiocarbon

Conference, University of California, Los Angeles and San Diego,

1976 .

5 Currie, L. A., Kunen, S. M. , Voorhees , K. J. , Murphy, R. B.

and Koch, W. F., Paper #7 in Conference in Carbonaceous Particles

in the Atmosphere , March (1978).

°Currie, L. A., "Environmental Radiocarbon Measurements",

Proceedings of the First Conference on Radiocarbon Dating with

Accelerators, University of Rochester, 1978, p. 372.

7 Radiocarbon measurements on small samples (mg-carbon) have

been applied to assess urban carbonaceous pollution from fossil

sources (Reference 5) and vegetative sources (J. A. Cooper, L. A.

Currie, and G. A. Klouda, to be published), and to define the

anthropoqenic component in marine sediments (J. Swanson, A. Fairhall

and L. A. Currie, to be published).

3

Lopes, J. S., Pinto, R. E., Almendra, M. E., and Machado, J. A

Proceedings of the Conference on Low Radioactivity Measurements and

Applications, High Tatras , Czechoslovakia (1975), p. 265.

9 Craig, H. , Geochim. Cosmochim. Acta _3 (1953) 53 ; Troughton

J. H., Proceedings of the Eighth International Radiocarbon Dating

Conference, Lower Hutt, M. Z. (1972) 1_, 421.

10 Damon, ?. K., Lerm.an, J. C., and Long, A., "Temporal

fluctuations of Atmospheric C-14: Causal Factors and Implications , " Ann. Rev. Earth and Planet. Sci., 6 437 (1978).
SO - BCMa - ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING

AND ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

I Energy Related Water Pollutant Standard Reference Materials

1 . a Complete Certification of Ocean Sediment SRM

No activity in this project during the past six-month period.

l.b.i Estuarine Sediment, Proposed SRM 1646

The material for Proposed SRM 1646, Estuarine Sediment was

collected by personnel of the Virginia Institute of Marine

Sciences at coordinates 37 11.1 N, 76 17.1 W in the Chesapeake

Bay. The material was freeze-dried and irradiated at 2.5

megarads

At NBS, the material was sieved through an 18 mesh sieve to

remove coarse contaminants, and then ball-milled to pass a 100

mesh sieve. The sieved material was blended for 45 minutes.

As anticipated, the chemical composition of Proposed SRM 1646

is significantly different from SRM 1645, River ' Sediment . At

present, Proposed SRM 1646 is being analyzed by neutron activation

analysis to determine the inhomogeneity of the 150 kg of processed

material. (See Appendix IV for certification of SRM 1645).

1 . b . i i Preconcentration and Separation of Sea Water Transition

Elements

A comprehensive report entitled, "The Quantitative Removal of the

Alkali and Alkaline Earth Elements from the Trace Transition

Elements in Sea Water Using Chelating Resin, and Its Application

to Analytical Instrumental Techniques," has been completed and

will be submitted to EPA for publication as an EPA Technical Repor
l.c Anions in Water SRM

No activity in this project during the past six-month period.

1 . d Anion SRM

No activity in this project during the past six-month period.

1 . e Anion and Trace Elements in Water SRM

SRM 1643, Trace elements in water, has been completely sold out.

The certification of a much larger trace element in water SRM

is now in progress.

1 . f The Role of Internal Standardization in Analysis of Aqueous

Samples Using the Inductively Coupled Plasma (TCP) Technique

As indicated in the previous report, the application of the ICP

technique to water analysis requires instrumental background

correction. This need arises because of background. shifts between

samples and standards which introduce systematic error. Spectral

scanning was shown to be an effective approach to this measurement

problem. However, since the total analysis time is lengthened,

the possibility of instrumental drift is increased. Preliminary

data has indicated that when such drift does occur, it is due

to variability of nebulizer aspiration. Under these conditions

similar behavior has been noted for groups of detector channels

in the direct reading spectrometer. Ratios of appropriate

channel pairs should, therefore, exhibit significantly less drift,

indicating the feasibility of internal standardization.

An operational rather than theoretical approach was chosen which

would examine the statistical behavior of all possible. channel- tochannel ratios during a normal analysis time period (40 min.).

Raw intensity data for three multi -element solutions were reduced

SO
by the NBS central computer to evaluate all possible intensity

ratios. These ratios as well as the raw intensities were then

statistically analyzed for random and normally distributed

variability [1]. Intensity ratios which exhibited significant

improvement in relative standard deviation (RSD) were grouped

as possible internal standard elements. Seven elements were

then ratioed to the best internal standard for each, and the

degree of RSD improvement over the raw intensity data was examined

at various signal to background ratios. The results are plotted

in Figure 17. The plot indicates that with proper choice of an

internal standard, the variability of response can be improved

upon by at least a factor of two, if the signal- to -background

ratio for the analyte element is ten or greater. Under such

conditions it has also been found that long-term (6 hrs) drift

of intensity ratios is limited to less than one percent while the

raw intensity drift was five percent. Frequency of restandardization can thus be reduced for routine analyses utilizing internal

standardization

Future developments will involve the application of new spectrometer and computer systems which will allow photographic as well

as electronic multi-channel detection of ICP emission. In the

multi-channel mode complete flexibility as to line choice,

observation height and automatic scanning background correction

will be available. Furthermore, spectral resolution will be a factor of ten better than the present direct reading spectrometer

allowing more complete separation of analyte emission lines from

those of the matrix.

Reference

[1] Filliben, ’’Testing Basic Assumptions in the Measurement

Process", in Validation of the Measurement Process , James R. DeVoe, Editor, ACS Symposium Series 65,

Washington, D. C., p. 50 (1976).

SI
o

o

Degree

of

RSI)

improvement

over

raw

intensity

data

examined

at

various

signal

to

background

ratios

for

seven

elements
SRMs for Qrg anic An a 1 y s i

s

2 . a / b Production of an Ague o us PAH SRM

Research on the feasibility of using PAH generator columns as

SRMs for PAH in water has been completed. We are now in the

procurement process for the production of this material. A copy

of the request for bid submitted to the Department of Commerce is

appended to this report (Appendix V)

.

Direct Injector for a Capillary Gas Chromatograph Used in Air and

Water Polluti o n Analysis

Normal injection techniques for capillary gas chromatography pre-

_ 7

elude the introduction of more than 100 nL (10 L) onto the chromatographic column. It is necessary, however, for trace analysis

of environmental materials to place a considerably greater volume

of sample (1 to 5 yL) onto the column in order to be able to

detect some of the low level organic compounds contained in the

sample. A number of special splitless injection techniques (such

as that developed by Grob and Grob) have been developed in order

to allow large sample volumes to be placed on the chromatographic

column without undue loss of system resolution. These splitless

methods have been shown. (Table 21) to yield systematic losses for

solutes with boiling points approximately 50 °C in excess of the

injector temperatures. Thus, since the maximum injector temperature is 550 °C, losses might be expected for any analytes with

boiling points greater than 400 0 C . The boiling points of some

polynuclear aromatic hydrocarbons (PAHs) which can be successfully eluted without on column losses are listed in Table 22. If

the compounds containing four or more rings are to be accurately

determined by gas chromatographic means, a new method of sample

injection will have to be used.

S3
TABLE 21

Comparison of Normal and Splitless Injector Techniques

Injector Temperature 550 °C

Compound Boiling Pt °C

Peak Area Splitless

Peak Area Normal

5-methyl tetradecane 264 1.3

n -hexadecane 287 1.3

n - eicosane 343 1.5

n- tetracosane 541 1.2

squalane 3 50 0.8

n-hexacosane 414 0.8

n -octacosane 440 0 .

If both injector techniques are temperature independent, the

ratio should remain constant.

TABLE 22

Boiling Points of Some Polynuclear

Aromatic Hydrocarbons

Number

Compound Boi 1 in g Pt of Rin

nap thalene 210 °C n phenanthrene 340 °C 5

1 , 2

, benzanthracene 4 5 5 °C 4

chrysene 448 °C 4

bent fa) pyrene >450 °C 5

coronene 525 °c -7

84
A direct injector is being developed at MBS which places a liquid

sample, of between 1 and 10 uL, on the head of the capillary

column, completely bypassing the normal heated injection port.

This injector consists of a pressurized glass tube in which the

head of the capillary column is placed and immobilized and a steel rod in which a sample cup has been inserted. This steel

rod slides through a pressure sealing 0-ring down the glass tube

until the head of the capillary column just touches the bottom of

the sample cup. The liquid sample, which had previously been

placed in the cup with a microliter syringe, is transferred to

the column by capillary action. This injector has been shown not

to adversely affect chromatographic resolution and preliminary

experiments indicate that the injector is boiling point independent.

2 . c Development of a Phenols - in-Water SRM

In some of our earlier reports we have presented preliminary

results of a study of the stability of some selected phenols

in distilled water. That study has now been completed and the

final results are given in Table 23. The data show that the

concentrations of phenol, o-cresol, and p-cresol remained constant throughout the 27 month study. The concentrations of

2-naphthol and 2 , 4 , 6 - trimethylphenol decreased with time. The

concentration of each of these five compounds in a 10 percent

benzene/90 percent hexane solution was constant throughout the

27 month period.

We have previously stated that the two most probable causes of

these losses were adsorptive losses to the walls of the glass

ampoules and biodegradation. Of these two probable causes, the

former seems to be the most probable cause for the observed

phenomenon. The two compounds that were lost from solution were

the least water soluble and most likely ones to adsorb on and

cling to the walls of the ampoules. On the other hand there is

no reason to assume that both 2-naphthol and 2 , 4 , 6- trimethylphenol

would be more susceptible to biodegradation than phenol or the

two cresols.

S 5
Stability

of

Selected

Phenols

in

Distilled

Water

o

u

>> <7 a 33

-i -r|

XI

r-j

x

-O

u

>> X

3 o

a x

i-l a O' a <r

>, m

n r-»

o

>1 CNI

C3

oca

U AJ Ml u CJ =

a s-t w

> a o

a a -a

So
We also have concluded that radiation sterilization is not a practical means of quenching any biological activity that might

occur in such solutions. The data given in Table 24 shows that

an irradiation dose of 1.5 megarads (suggested by D. Woodward,

Neutron Products Inc., Dickerson, Maryland) causes molecular

degradation within the solution.

Given this information, we have decided to initiate a similar

study using a coal by-product water, where we have added 1-100

ppm of the same five compounds plus several other hydroxylated

aromatics. The purpose of this study will be to determine whether

the highly water soluble compounds again show a high degree of

stability and if the increased organic content of this matrix

will enhance the stability of less soluble compounds such as

2-naphthol and 2 , 4 , 6 - trimethylphenol and some hydroxylated PAKs

.

2 . d Development of SRMs for Organics in Sediment and Biota

More data on the Muscle Intercomparison Exercise are being

compiled, and the compilation should be available for the next

semi-annual report.

y

2 . e Spectroscopic Certification Technique for Analysis of Trace

Organics in Water SRM

No activity in this project during this six-month reporting

period

.

3

~
Degradation

of

Aqueous

Solutions

of

Phenols

Due

to

co4J

CDg

4J

cO

<D

S-i H

G

O

•H

CO •H

"O

CO PS

Ou C

o O -r-1 3 4J a co

'/) -O M CO O OS 4

a

s

COa

V-i H

cr» ctn in vio

I /-N •H 4J a g

c CO <U o u s

•H 4-)

J-) jj CO

CO CO CD U o hJ *<r r^. cn CN cn u P-i H • • • • • tc oO cn o CN CN 5 G £ rH r~1 CJ T3 o '— c a •H o 3 4J CJ O CO

1 a

G •H £

O T) a

•H CO s

4a PS H

CO 03 }a o a hJ

4-> z h "• OO

m 00 pH H cp • • •

<D o CN cn 00

CJ T3 C 'w' CN m cn vO G r* O

O 3 •ri o O 4-J Fn 03

a o 0

•H •H U iJ 4J C3 -3 /*—

3 U 3

00 s i-j 33 o cn cn <r

•H G 33 cx • • • • • > < r-1 <r <r pH CO

cO U 'w' CN m cn r- cn

t-i o ou 1 r—

>>u

Z) —H 2

3

"0 r-H rH si u

3 a iJ •J — r— 7) 73 si 1 3 o 1) j S*

3. 3 H H P' CJ CJ

1 i NT

">J "H.

1 i O

I CN CN

cn T3

c3H

COCD

<u m

CN

TO

-3U

ss
APPENDIX IV

Department nl Commerce

Juanita ,\J. Kreps

Secretary

iitional Burenoi ol Standards

ir'rnesi Amrner Dtrennr

^iirsait of j^imtrlarris

(Anali ms

Standard Reference Material 1645

River Sediment

This Standard Reference Material is intended for use in the calibration of methods used in the analysis of river sediment and materials with similar matrices. The material has been freeze dried and is now essentially free from moisture. The certified values given below are based on measurements made on a dried sample of at least 100 mg for the trace elements and for a 1-g sample for iron and chromium.

The values are based on the results of 6 to 30 determinations by the analytical techniques indicated. The

estimated uncertainties include those due to sample variation, possible method differences, and errors of

measurement (see Preparation and Analysis).

Element . . Mg/g . Element Mg/g . . _

CadmiunV d 10.2 ± 1.5 Thorium6 1.62 ± 0.22

Copper

6 c 109 ± 19 , Uranium6 1.11 ± .05 Lead

6 d 714 ±28 Vanadium1 c 23.5 ± 6.9 Manganese

6 c 785 ± 97ad

Zinc 1720 ± 169

Mercury

1 c 1.1 ± 0.5 Weight %

Nickel

6 d 45.8 ± 2.9 Chromium6 c 2.96 ± 0.28

Thallium

6 1.44 ± 0.07 y a c Iron 11.3 ± 1.2

Atomic Absorption Spectrometry

b

' Isotope Dilution Mass Spectrometry Neutron Activation Analysis

d

' Polarography

The overall direction and coordination of the technical measurements leading to certification were performed

under the chairmanship of J. K. Taylor.

The technical and support aspects involved in the preparation, certification, and issuance of this Standard

Reference Material were coordinated through the Office of Standard Reference Materials by W. P. Reed.

Washington, D.C. 30234

November lb, 1978

(over)

S9

J. Paul Cali, Chief

Office ot Standard Reference Materials
Instructions for Use

The material, as received, is essentially free from moisture. In case of exposure to moisture, it should be dried

without heat to a constant weight before using. Recommended procedures for drying are: (1) drying for 24

hours using a cold trap at or below -50 °C and a pressure not greater than 30 Pa (0.2 mm Hg); (2) drying in a

desiccator over P;Os or Mg(C 104) 2 . When not in use, the material should be kept in a tightly sealed bottle and

stored in a cool, dark place.

Material of this kind is intrinsically heterogeneous. Consequently, the analyst should endeavor to minimize any

segregation by thoroughly mixing the contents of the bottle by shaking/and rolling before each use. In addition,

when taking a portion for analysis, the analyst should strive to remove as representative a sample as possible.

Preparation and Analysis

This SRM was prepared from material dredged from the bottom of the Indiana Harbor Canal near Gary,

Indiana. This material was screened to remove foreign objects, freeze dried, and sieved to pass a No. 80(180^m)

screen. This material was thoroughly mixed in a V-blender, bottled, and sequentially numbered. The material

has been radiation-sterilized to minimize alteration from biological activity.

Randomly selected bottles were used for the analytical measurements. Each analyst examined at least 6 bottles, some of them measuring replicate samples from each bottle. No correlation was found between measured values

and. the bottling sequence. The results of measurements on samples from different bottles did not appear to

differ significantly from sub-samples within the bottles. Accordingly, it is believed that all bottles of this SRM

have substantially the same composition. The analytical methods employed were those in regular use at NBS for

certification of Standard Reference Materials, except as noted below. Measurements and calibrations were made to reduce random and systematic errors to no more than one percent, relative. The uncertainties of the

certified values listed in the table include those associated with both measurement and material variability. They

o represent the 95 percent tolerance limits for an individual sub-sample, i.e., 95 percent of the sub-samples from a

unit of this SRM would be expected to have a composition within the indicated range of values 95 percent of the

time.

The following values have not been certified because either they arc not based on results of a reference method,

or were not determined by two or more independent methods. They arc included for information only.

All values are in units of ,ug/g of sample, unless otherwise indicated.

Antimony (51) Potassium (1.2 wt. %)

Arsenic (66) Scandium (2) Cobalt (8) .V Sodium (0.55 wt. %)

Lanthanum (9) '

90
The values listed below are based on measurements made in one laboratory, and are given for information only.

While no reason exists to suspect systematic bias in these numbers, no attempt was made to evaluate such bias

attributable to either the method or the laboratory. The method used for each set of measurements is also listed. The uncertainties indicated are two times the standard deviation of the mean.

Kjeldahl Nitrogen

Total Phosphorus

Loss on Ignition (800 °C)

Oil and Grease (Freon)

Chemical Oxygen Demand (Dichromate)

(0.0797% ± 0.0048)

(.051% ± .0014)

(10.72% ± .28)

(1.71% ± .26)

(149,400 mg/ kg ± 9,000)

The methods used are:

Total Phosphorus - ASTM Method E-350.

Chemical Oxygen Demand (Dichromate) - Standard Methods for the Examination of Water and Waste

Water, 14th Edition (1975), Section 508, page 550. Oil and Grease (Freon 113 Extraction) - (bid, , Section 502, page 518. The following values are not certified, but are given to describe the matrix of the material: Si02 - 51%;

MgO - 4%; A1 2 03

- 4%; CaO - 4%.

H. L. Rook supervised collection, freeze drying, and homogenization of the SRM. The following members of

the staff of the NBS Center for Analytical Chemistry performed the certification measurements: T. J. Brady;

E. R. Deardoff; L. P. Dunstan; M. S. Epstein; R. Filby; M. Callorini; E. L. Gamer; T. E. Gills; J. W. Gramlich;

R. R. Greenberg; S. H. Harrison; G. J. Lutz; L. A. Machlan; E. J. Maienthal; T. C. Rains; H. L. Rook; T. A.

Rush; and W. P. Schmidt.

The development work, proceeding the certification of the SRM, was supported by the Environmental

Protection Agency under an Interagency Agreement.

91
2154

•j s DEPARTMENT of commerce

national bureau or stanoards

PROCUREMENT SECTION

WASHINGTON. D C 20234 Q PURCHASE ORDER'

DELIVERY ORDER

DATE ISSUED

PLEASE ADDRESS SHIPMENT AS SHOWN IN THIS BLOCK

SU A

P D

P 0

L

r

bid list attached

E S R S s L

Telephone:

J

iIP 3 SHiPPiNGrArOORFSi

NATIONAL BUREAU OF STANDARDS

BLDG 301

(VIA COMMERCIAL CARRIER)

Route 270 and Quince Orchard R<J. Gaithersburg, Maryland 20760

(VIA U.S. MAIL)

WASHINGTON. O C. 23234

5. SUBMIT INVOICE IN DU=LiCATc

SHOWING ORDER NUMBER TO'

NATIONAL BUREAU OF STANDAP.OS

ACCOUNTING DIVISION

WASHINGTON. O. C 2C234

6 COST CENTERtS)

5030701

NSS USE ONLY

7 . OBjECT CLASS 8 | certify mat the cost o( trus purchase is property cnaraeapie against

the Co:' Center i^pcnted

tSlGNAI Cf'£ Cr AU ffU 1 -' J' d < '-'''OVIAG CrrtZi.*'

Date 10-30-73

13. INVITATION NO. 14. DATE OE 3ID

W. CONTRACT NO. 18. CODE

O

9. REQ. NO. 503-505-79

10. DIV/SEC

. 503

12.W.E. May, A105, Chemistry

15 F O 3. PO;NT

-

19. DELIVERY TIME 20. DISCOUNT

n. WORK CSCt?

16. SHIP VIA

I ITEM NO.

1.

22. ARTICLES OR SERVICES Generator Columns for Polynuclear

Aromatic Hydrocarbons to be fabricated

in conformance with specifications

cited in the attachments.

Suh.ect to attached Terms and Conditions of Purchase Order

23.QUANTITY

720

1 ?

24.UNIT

25.UNIT PRICE AMOUNT

ea

28UNITED STATES OF AMERICA

By —

S3 lI.T.3 ' $30.00 $21,600

29 total i s $21 , 500.

Cv)N l Mai; 1 iru» q» » iq fl
SPECIFICATIONS

Generator Columns for Polynuclear Aromatic Hydrocarbons

MATERIALS

Gla ss Deads (11000 grams) - Glass port M, 60-80 mesh,

#8501-6304, Hewlett Packard Corp., Avondale Division

# 316 Stainless Steel Tubing (400 meters) - 1/4 in (6.4

mm) OD . , 4 mm ID . , Fittings for Columns (all fittings, nuts, and ferrules,

•should be Swagelok 316 SS)

a. Porous Teflon Plugs (800) - approximately 4 mm diameter, but should be cut to fit snuglv into 1/4 to

1/1 6 inch reducing union.

b. 1/4 in. female nuts and ferrules (1.600) c. 1/4 to 1/16 in. reducing union (800)

d. 1/4 to 1/16 in. reducing union with 5 micrometer

(0.005mm) snubber 0.600)

e. 1/16 in. cap. Q.600)

Chemicals (40 grams of each)

Anthracene, I, 2 benzanthracene and 3,4 benzpyrene are

to be used for coating three separate .batches of glass

beads. These compounds must be at least 98.5 mole %

pure. 5 mg of each compound should be sent to NBS for

a purity check.

Reagents - 70 liters methylene chloride', 50 liters

methanol, 14 liters 1 % HF, 400 liters water . All

organic solvents shall be reagent grade. The water

used shall be distilled over alkaline permanganate.

Sieve - No. 45 U . S

. Standard Sieve or equivalent (0.0139

in = 354 ym opening)

PREPARATION OF GENERATOR COLUMNS

Prescription of Columns

V 20 stainless steel columns shall be made. Each column shall

be 50 cm in length and have an internal diameter of 4 mm.

Cleaning Columns : The interior of each column shall be cleaned initially with

soap and water and thoroughly rinsed. The columns should

_

then be purged with 30 mL of methanol, methylene chloride and

hexane respectively. All column fittings shall be cleaned by

5 minutes of ultrasonic agitation in methylene chloride.

Cleaning Beads

The beads shall be cleaned by 5 minutes of ultrasonic agitation

in 14 liters of each of the following in succession: methylene

o ^
chloride, metha l, water, 11 hydrofluoric „cid, water, and

methanol respectively, discarding each solvent after agitation.

The beads shall then be divided into three equal batches and

stored in a clean glass container.

Coating Deads

Each baton of

with a single

immersing the

of the PAH of

The methylene

evaporator

beads (one third of 14000g) shall be coated

polynuclear aromatic hydrocarbon (PAH) by

beads in 10 liters of a 0.43 iwt/wt) solution

interest dissolved in methylene chloride,

chloride shall then be evaporated with a rotary

After evaporation of the methylene chloride is complete,

the residue shall be sieved with a §45 U.S. Standard Sieve

to separate the coated beads from excess PAH compound. A

sub sample of 10 grams of coated beads from each of the

three batches shall be sent to NBS for analysis prior to

packing columns.

Packing Columns

After receiving clearance from NBS, the coated beads of a

single PAH shall be dry-packed into 240 of the previously

prepared stainless steel tubes. Each column shall contain

15-16 grams of beads. One end of the column (inlet) shall

be capped with a 1/4 to 1/16 inch reducing union that has

been fitted with a porous Teflon plug. The opposite end

shall be capped with a 1/4 to 1/16 in-ch reducing union that

has been fitted with a 5 micrometer stainless steel frit

(snubber)

Equilibrating Columns

Each column shall be thermostated at 50 °C and purged with

500 mL of distilled water. After equilibration, each end

of the colpmn should be fitted with a 1/16 inch Swagelok

cap.

General Comments

Each of the three sieved batches of PAH coated glass beads

must be coated with 0.3 to 0.5% of the respective compound.

The columns for each of the three compounds shall be

numbered according to the sequence of packing (1-240 ) .
UNITED STATES DEPARTMENT OF COMMERCE

Nation."il Dun1 a u of Standards

'.V.isMirg'on, C. Du23a

October 2, 1978

MEMORANDUM FOR Procurement Section

2Xh NV

From: W.E. May

Subject: Justification for Procurement of

Generators for Polynuclear Aromatic

Hydrocarbons (PAH)

Since many PAH are known to be carcinogenic

or cocarcinogenic , there is justifible concern regarding the measurement of extremely

low concentrations of these compounds in

water. The PAH generator columns, prepared

as specified will be issued by NBS ,as an SRM.

It will enable investigators to generate known,

accurate concentrations (in the 1-50 ppb range)

of a three, four, and five-condensed ring PAH

in water, and use these certified concentrations

for calibrating instrumentation and validating

methodology

»

9 5

i
BID LIST

S; 4

1. Analabs

80 Republic Drive

North Haven, Conn. 06473

(203) 288-8463

Contact: Mr. William Cullen

2. Applied Science Lab.

P .0 . Box 4 4 0

State College, Pa.' 16001

(814)238-2406

Contact: Sharon McKinley

3. Waters Associates

Milford, Mass.

(617)478-2000

Contact: Ken Alden
S

1 - BCMb - ENERGY RELATED POLLUTANTS AND EFFECTS MONITORING .AND

ASSOCIATED METHODS AND TECHNIQUES DEVELOPMENT

\ Develop Organic Standard Reference Mater ials for the

Cali b

r

ation of Energy-Related Water Pollutant Measurement

Me thods

No activity under this task in the present semi-annual report.

o

"
80 -HCN- RADIOLOGICAL POLLUTANT QUALITY ASSURANCE

} Develop C n 1 i b r a t ed Radioactive Materials for Radiological

Pollution Associated with Nuclear and Coni Energy Sources

and Production

The goal of the program is to provide measurement traceability,

through the U. S. Environmental Protection Agency at Las Vegas

(EPA-LV), for certain radionuclides not included in other programs.

These radionuclides were chosen because they are released into the

environment from nuclear power reactors (such as light -water

reactors), coal burning plants, or other, related, sources. The

program for FY 76-80 is summarized in Table 25.

1 . a Solution of Natural Isotopic Uranium, and Solution of

Plutonium- 241

The uranium oxide (U0~) has been purified, solutions prepared and

shipped to EPA. The isotopic composition of the uranium has been

certified by mass spectrometry, and the total uranium concentration

has been determined by isotope-dilution mass spectrometry. A copy

of the Report of Calibration for this material is attached as

Appendix VI

The EPA-LV has received the ampoules and Reports of Calibration

of the calibrated solution of plutonium- 241 . I\'e are continuing

to measure the half life of plutonium- 241 by means of measurements

of the f,rov;*:n 0 f americium-241.

l.b Fly< - Ash from Coal Combustion

Fly ash from the combustion of eastern United States coal is being

assayed for radium-226 and radium-22S. Homogeneity tests of the

l ad i oact ivity in SRM 1655, Trace Elements in Coal Fly Ash, have

98
TABLE 2

S

cl Radiological Pollutant Quality Assurance

Performing Agency: National 3ureau of Standards

(E-AP ID No. 79 BCN)

[Revised Milestones as of June 1978]

A - due ; A - completed

Task 1. Radiological cali- FY 76 FY 77 FY 78 FY 79 FY 80

brated radioactive materials $k 91 50 50 50 30

1.1 Establish lab

facility

210. 1.2

1.3

Po solution

?26

Ra soil.

Mixed gamma solution,

239.

Pu solution

1.4 Mixed gamma soil

1.5 Natural U solution,

3 u solution

,b

24 A

1.6 Fly ash from coal

232

1.7

1.3

Th solution.

Mixed radionuclide solution

210

?b solution,

'Cm solution,

^Cn solution

A

A

A

Ai

k

A

A

A

A

A

A

A

. :: sconces or all Standards are subject to satisfactory performance as teamed by N3S Standard Reference Material criteria.

icoitional $31k was allocated for (i) traceability testing, which

c continuing program, and (ii) preparation of the fly ash

u o
been performed by the Radioactivity Section and the material

found to be satisfactorily homogeneous for this program. Gc(Li)

gamma -ray measurements for the determination of radium-228 are

in progress. Radon gas counting of rad i ochcmi ca 1 ly processed

samples to determine the radium-226 concentration is nearing

completion

2 Measurement Traceability Studies with the Quality Assurance

Branch of EPA-LV

The NBS conducts tests with the Quality Assurance Branch (QAB)

to ascertain whether radioactivity measurements made by the QAB

are traceable to NBS. These studies are on radioactive test

sources, with known but undisclosed values, that are sent to the

QAB by NBS, and on radioactivity standards prepared by QAB and

sent to NBS for confirmatory measurements. The criteria for

conducting the studies are given in an appendix to the NBS-EPA

interagency agreement.

The status of these studies for this six-month period is given

in Table 26. NBS has provided the QAB with six test sources of

undisclosed value, and one result has been reported to NBS. A copy

of the traceability statement for the completed test is attached as

Appendix VII.

100
TABLE 2o

Status of Traceability Studies of Radioactivity

Measurements by

for the Period

the Quality Assurance Branch (EPA-LV)

of July 1 through December 21, 1978

Test Sources Sent Result Reported

Parent Radionuclide Form Radionuclide QAB/NBS

Cobalt - 58 solution Hydrogen-3 1.010

Strontium- 89 solution

Cerium- 141 solution

Lead- 2 0 3 solution

Uranium solution

Plutonium-238 point source

101
FCViM NPS-U3

(R£V. 12-66) APPEND I

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

WASHINGTON, D.C. 20224

REPORT OF CALIBRATION

Uranium Solution of Natural Isotopic Composition

prepared for the

Quality Assurance Branch

U.S. Environmental Protection Agency

Las Vegas, Nevaaa

This solution consists of uranium of natural isotopic composition in appro/-

imately 4.9 g of 1 M HNO3

in a flame-sealed borosi 1 icate-gl ass ampoule.

The solution was prepared in the following manner. Uranium tri oxide was dissolved in 4 M HNO

3

, uranium was precipitated as hydrated oxides from u> ,,J solution with carbonate-f ree NH^OH, and the precipitate was then dissolved

( 3 ) in 4 M CH

3

COOH. The uranium was purified in June 1978 by the method of Mo'»rc

starring with a solution of 1 M CH

3 CCOH containing 15 mg uranium per gram ' yl acid. Uranium was next repreci pi tated from 0.5 M HNO

3

with MH^OM, and th<’

precipitate was dissolved with 2 M HNO

3

. The final solution was prepared •'/ filtering this solution, diluting it with water to 1 M in HNO

3

, and then

adding 1 M HNO 3

until the desired uranium concentration was reached.

Six of the 315 ampoules containing aliquants of the final solution were a

,l V

ecl for uranium isotopic composition and total uranium concentration by isotn;» f-- dilution mass spectrometry ^

' in the Inorganic Analytical Research Division,

National Bureau of Standards, in September 1978. Summaries of tne resul : these assays are given in Tables 1 and 2.

The radioactivity concentrations of ^\|, ^^U, and ^^U were calculated n'- ln 9

the conversion factors and constants that are listed in Table 3. The cal'

values are given in Table 4. The radioactivity concentration of each i so 1 1S

equal to its al pha-particl e-enii ssion rate per gram of solution, witnin tmstated uncertainty.

For the Director

w. b. ihann, Chief

Radioactivity Section

Center for Radiation Res; ''' M

10 2

Novemoer 1 97 S
and the Atomic Mass.

- 2 -

TABLE 1. Summary of the Isotopic Composi ti on^ a 5

b

^

234

y 235y 238y

Atom percent 0.0052 - 0.0002 0.7204 ± 0.0006 99.2743 - 0.0008

Calculated 0.0051 - 0.0002 0.7114 - 0.0006 99.2835 ± 0.0008

mass percent

Atomic mass of uranium = 238.0287 amu

a Whe indicated uncertainties are composed of the linear sum of statistical

error in the mass spectrometric measurements at the 95-percent confidence

level and the sum of conceivable systematic errors.

Uranium-236 was not detected. An upper limit of 0.00005 atom percent was

estimated on the basis of the noi se-to-signal ratio.

TABLE 2. Uranium Concentration data (a)

Mi Hi grams of U per

gram of solution

3.4776 t 0.0035

Milligrams of 288

U per gram of sol uti on

0.02474 t 0.00003

Milligrams of 238

U

per gram of solution

3.4525 - 0.0035

a ^The indicated uncertainties are composed of the linear sum of statistical

error in the mass spectrometric measurements at the 95-percent confidence

level and the sum of conceivable systematic errors.

TABLE 3. Relevant Conversion Factors and Constants.

Hal f 1 i fe of 23 ^U

Hal f 1 i fe of 238

U Hal f 1 i fe of 23o

U Atomic mass of 238

U Atomic mass of 238

'J Avagadro constant

Length of tropical year

a ^oased on the ephemeris second.

(2.445 - 0.010} x 105

y

(3)

(7.038 - 0.005) x 108

y

(4 >

(4.468 - 0.003) x 109

y

(5)

(235.043925247 - 0.000002552) amu^

(238.050785782 - 0.000002361) amu (6)

(5.0220978 ± 0.0000010) x 1023

3.155593 x 107

s (a)

103
- 3

-

TABLE 4. Calculated Isotopic Uranium Radioactivity Concentrations, October 191

^

4

U (s~*g~M 235y ( s -lg-l) ^38y ( S "lg-1

)

42.9 t 0.3% (b) 41.3 - 5.2% (a) (d: 1.98 T 0.4%

a Whe indicated uncertainty is the linear sum of the uncertainty in the masspercent value and three times the uncertainty in the half-life value.

b Whe indicated uncertainty is the linear sum of the uncertainty in the concentration value and three times the uncertainty in the half-life value.

References

(1) F. L. Moore, "Liquid-Liquid Extraction of Uranium and Plutonium from

Acetate Solution with Tri i so-octyl ami ne" , Anal. Chem., 32(9), 1075

(1960).

(2) E. L. Garner, L. A. Machlan, and W. R. Shields, Uranium Isotopic

Standard Reference Materials , MBS Special Publication 260-27*, Mational

Bureau of Standards, Washington (April 1971).

(3) Y. A. Ellis, "Nuclear Data Sheets for A=234", Mucl . Data Sheets, 21,

493 (1977).

(4) M. R. Schmorak, "Nuclear Data Sheets for A=231, 235, 239“, Nucl . Data Sheets , 21 , 91 (1977).

(5) Y. A. Ellis, "Nuclear Data Sheets for A=238" , Nucl. Data Sheets, 21,

549 (1977).

(6) A. H. Wapstra and K. Bos, "The 1977 Atomic Mass Evaluation, Part I.

Atomic Mass Table", Atomic ana Nucl. Data Tables , 19 , 177 (1977).

(7) Recent, unpublished value, National Bureau of Standards.

104
U.S. DEPARTMENT OF COMMERCE

NATIONAL. DUREAU OF STANDARDS

WASHINGTON. D.C. 20234

Hydrogen-3 Radioactivity Test Solution

prepared for the

Quality Assurance Branch, USEPA

Las Vegas, Nevada

This test solution consisted of approximately 5 grams of water containing

hydrogen-3. The solution wa s contained in a flame-sealed borosil icateglass ampoule.

Material from another aliquot of this test solution was quantitatively diluted

with triple-distilled water and the radioacti vity concentration of hydrogen-3

in the dilute solution was determined by liquid-scintillation counting. Ten

* vials prepared from this material were intercompared with ten vials prepared

from MBS Standard Reference Material 4926.

The radioactivity concentration of hydrogen-3 in this test solution, as of

0700 EST April 19, 1973, was

*1 .748 x 10 5 s’V 1 ± 2 . 8%*

.

The total uncertainty in the radioactivity concentration value, 2.8 percent,

is the linear sum of 0.2 percent, which is the limit to the random error of the

liquid-scintillation comparative measurements at the 99-percent confidence level

(2.6 Sm , where Sm is the standard error computed from 6 sets of 20 measurements),

2.5 percent, which is the uncertainty associated with SRM 4926, and 0.1 percent,

which is a contribution to the uncertainty due to source preparation.

A half life of 12.35 ± 0.01 years [0RNL/NUREG/TM-1 02 , 19, August, 1977] was used

for the decay correction. The estimated systematic error given above includes a 0.8-percent contribution due to the uncertainty in the half life and the 16.62-

year decay.

The Quality Assurance Branch of the U.S. Environmental Protection Agency (EPA)

measured the radioactivity concentration of this solution by means of comparative

liquid-scintillation measurements, and found it to be, as of 0700 EST April 19,

1978,

1.767 x 10 5 s'V 1 ± 5.6%.

10 5

i
2

The uncertainty in the EPA value, 5.5 percent, is the linear sum of 0.3 percent,

which is the limit to the random error of the liquid-scintillation measurements

at the 99-percent confidence level (3.250 Sm , where S m is the standard error computed from 10 determinations), and 5.3 percent, which is the estimated upper

limit of conceivable systematic errors.

The ratio of the EPA to NBS values, 1.010, demonstrates traceability of the EPA

to NBS to within 1.0 percent as of April 1978, and lies within 5 percent of the

NBS value as specified in the Appendix "Traceability Studies" of the NBS-EPA

Interagency Agreement of April 20, 1976.

For the Director,

r

Vi. B. Mann, Chief

Radioactivity Section

Center for Radiation Research

August 15, 19

-7 n

/ O

106


WERT

BOOKBINDING

MIDDLETOWN PA SEPT 81 W> ft* Quality Bound