Library, r N.W.Bldg B'l3l96 taken fr

NBS

ecltnical ^lote 275

IANTITATIVE SEPARATIONS: TITRIMETRY, 6RAVIMETRY,

LME PHOTOMETRY, SPECTROPHOTOMETRY, GAS

ILUTION AND ISOTOPIC PREPARATIONS,

LY 1964 TO JUNE 1965

S. DEPARTMENT OF COMMERCE

iTIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

Bureau of Standards is a principal focal point in the Federal Government for ing maximum application of the physical and engineering sciences to the advancement of technol. -\

in industry and commerce. Its responsibilities include development and maintenance of the national

standards of measurement, and the provisions of means for making measurements consistent with

those standards; determination of physical constants and properties of materials; development of

methods for testing materials, mechanisms, and structures, and making such tests as may be necessary, particularly for government agencies; cooperation in the establishment of standard practices

for incorporation in codes and specifications i advisory service to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Govern- ment; assistance to industry, business, and consumers in the development and acceptance of com

mercial standards and simplified trade practice recommendations; administration of programs in cooperation with United States business groups and standards organizations for the development

of international standards of practice; and maintenance of a clearinghouse for the collection and

dissemination of scientific, technical, and engineering information. The scope of the Burea . - activities is suggested in the following listing of its three Institutes and their organizational units Institute for Basic Standards. Applied Mathematics. Electricity. Metrology. Mechanics. Heat. Atomic Physics. Physical Chemistry. Laboratory Astrophysics.* Radiation Physics. Radio Standards

Laboratory:* Radio Standards Physics; Radio Standards Engineering. Office of Standard Referei < < Data. Institute for Materials Research. Analytical Chemistry. Polymers. Metallurgy. Inorganic Materials. Reactor Radiations. Cryogenics.* Materials Evaluation Laboratory. Office of Standard R« ence Materials. Institute for Applied Technology. Building Research. Information Technology. Performance

Test Development. Electronic Instrumentation. Textile and Apparel Technology Center. Technical

Analysis. Office of Weights and Measures. Office of Engineering Standards. Office of Invention and

Innovation. Office of Technical Resources. Clearinghouse for Federal Scientific and Technical

Information.**

•Located at Boulder, Colorado, 80301. •Located at 5285 Port Royal Road, Springfield, Virginia, 22171.
NATIONAL BUREAU OF STANDARDS

Technical Note 275

ISSUED DECEMBER 27, 1965

QUANTITATIVE SEPARATIONS: TITRIMETRY, GRAVIMETRY,

FLAME PHOTOMETRY, SPECTROPHOTOMETRY, GAS

EVOLUTION AND ISOTOPIC PREPARATIONS,

JULY 1964 TO JUNE 1965

Edited by Oscar Menis

Analytical Chemistry Division

Institute for Materials Research

NBS Technical Notes are designed to supplement the Bureau's regular publications program. They provide a means for making available scientific data that are of transient or limited interest. Technical Notes may be

listed or referred to in the open literature.

For sale by the Superintendent of Documents, Government Printing Office

Washington, D.C., 20402 - Price 50 cents
FOREWORD

The Analytical Chemistry Division was

established as a separate division at the National

.Bureau of Standards on September 1, 1963, and became

part of the Institute for Materials Research in the

February 1, 1961). reorganization. It consists at

present of seven sections and about 85 technical

personnel encompassing some 30 different analytical

competences from activation analysis and atomic

absorption to vacuum fusion and x-ray spectroscopy.

These competences, and in turn the sections which

they comprise, are charged with research at the forefront of analysis as well as awareness of the practical sample, be it standard reference material or

service analysis. In addition it is their responsibility to inform others of their efforts.

Formal publication in scientific periodicals

is highly important. In addition, however, it has

been my experience that informal, annual summaries

of progress describing efforts of the past year can

be very valuable in disseminating information. At

the National Bureau of Standards such publications

fit logically into the category of Technical Note.

In 1965 we plan to issue these summaries for all of

our sections. The following is the first annual

report on progress of the Quantitative Separation

Section.

W. Wayne Meinke, Chief

Analytical Chemistry Division

li
PREFACE

This is the first of a series of annual progress reports

dealing with the activities of the Quantitative Separations

Section of the Analytical Chemistry Division. In the general

reorganization of the Division this section was formed in

November 1961_|.. R. A. Paulson was the active section chief

until January 1965 and since then 0. Menis joined as the

chief of this section. The personnel of this section consists

of twelve scientists. A roster of this group is presented

in the section on personnel.

The work described in this report covers the fiscal

period of 1965 and encompasses the following areas of

competences: titrimetry, gravimetry, flame spectrophotometry,

spectrophotometry, gas components in metals. It includes

also areas dealing with uranium and plutonium chemistry. Its

major effort during the past year was to establish the most

[accurate values for the chemical composition of over twentyfive standard reference materials by means of the above

listed analytical disciplines. The group performed the

[analysis and ascertained the accuracy of the methods selected

for certifying values for a given composition of the material.

The section's efforts included also assisting in the

procurement of these materials, determining their homogeneity,

preparing the material in a form most suitable for sampling

and finally evaluating the efforts of the outside laboratories

which cooperated in checking the values prior to the final

certification of the analysis. Some of these functions have

been now taken over by the Office of Standard Reference

Materials

.

In certain areas of competences, or analytical chemistry

pisciplines, additional efforts are currently being made to

tmprove the accuracy and to facilitate an increased production

of standard reference materials. This involved the procurement and installation of additional instrumentation. In the

'determination of gas components in metals a new instrument

|makes it feasible to increase the output of samples by a fcenfold factor. In the area of spectrophotometry, methods

Wov ultra high sensitivity at the nanogram level, and for

[high precision spectrophotometry are being developed. For

thigh precision gravimetry, a the rmogravime trie analysis

j&pparatus was also obtained and is being tested. Similarly,

|!in flame photometry and atomic absorption, instrumentation

(has been procured to assist in analysis of trace elements

present in a variety of standard reference materials.

111
While the major effort of this section has been expended

during the past year in the certification of standard

reference materials, work has been initiated to expand this

effort into those areas of study which would also assure

greater accuracy and sensitivity in the analysis of new and

renewal NBS standards.

In order to specify adequately the procedures , it has

been necessary to occasionally identify commercial materials

and equipment in this report. In no case does such identification imply recommendation or endorsement by the National

Bureau of Standards, nor does it imply that the material or

equipment identified is necessarily the best available for

the purpose.

Oscar Menis, Chief

Quantitative Separations Section

IV
TABLE OP CONTENTS

PAGE

1. TITRIMETRY 1

Separation Problems 1

Determination of Cobalt in High Temperature

Alloy 1

Determination of Iron in High Temperature

Alloy 1

Complexometric Titration of Calcium and

Magnesium 3

2. GRAVIMETRY 6

Determination of Aluminum in Feldspar 8

Stoichiometry of Uranium Oxide 8

Thermogravimetric Analysis 8

Preconcentration of Hafnium in Zirconium 9

3. FLAME PHOTOMETRY 12

New Instrumentation 12

Determination of Alkali and Sr in Clays llj.

Determination of Alkali and Strontium in Cements . 16

Determination of Alkali Elements in Feldspar

(70a) 16

I+. SPECTROPHOTOMETRY 18

High Sensitivity Spectrophotometry 19

Introduction 19

Cell Design 20

Boron-Curcumin System 21

Beryllium Acetylacetonate 21

Role of blank 21
TABLE OP CONTENTS (Cont'd)

PAGE

Determination of nanogram quantities of

beryllium with acetylacetonate 21

Analysis of NBS samples 22

High Precision Spectrophotometry 23

Introduction 23

Determination of High Concentration of Nickel. 2\\

General Spectrophotometry 26

Determination of Low Concentration of Nickel . 26

Determination of Trace Elements in Standard

Reference Materials 27

Determination of Antimony by the Brilliant

Green Procedure 30

Analysis of Trace Quantities of Manganese and

Silicon in Titanium Alloys 31

Conclusion 32

5- GASES IN METALS 33

Determination of Gases in Ferrous Alloys .... 33

Types of Materials 33

Evaluation of Results 33

Determination of Gases in Titanium and Titanium

Alloys 36

Apparatus 37

Determination of Nitrogen in Ferrous Alloys by

Alkaline Fusion 38

Introduction 38

Apparatus and Method [j.0

Initial Results on Nitride Determination ... lj.0

VI
TABLE OP CONTENTS (Cont'd)

PAGE

6. ASPECTS OP ANALYSIS ASSOCIATED WITH STANDARD

REFERENCE MATERIALS lj.1

Introduction I4.I Preparation and Conversion of the Material to

a Suitable Sample Form I4.3 Steel Samples i_|_3

Cast Iron i_j_i_j_ Spectrographic Samples Lu\|_

White cast iron \\%

Carbon and alloy steels \\%

Copper-base alloys [|_5

Limestone and Dolomite \\%

Rocks and Ceramics I4.5 Actinide Elements I4.5 Homogeneity Studies \\%

Ferrous-Base Materials I4.6 White cast iron standards Lj.6 Maraging steels . I4.7 High- temperature alloys I4.7 Copper Base Materials i|.9

Limestone, Dolomite and Clays Sh

Lime stone -homogeneity SkFeldspar-stability . 5^4- Clay SS

Cooperative Work with Outside Laboratories .... 5&

Vll
TABLE OP CONTENTS (Cont'd)

PAGE

7. URANIUM UMPIRE PROGRAM 58

Status of Current Program 58

Participation in the AEC-GAE Program 58

8. URANIUM AND PLUTONIUM ISOTOPIC STANDARDS 61

Introduction 61

Assay Process of Uranium Oxide Prior to Blending

of Isotopes 61

Preparation of Isotopic Mixtures 63

Plutonium Isotopic Standard 9l±Q 6l\.

Preparation of Plutonium Isotopic Standards. . . 6I4. Separation of Americium 6I4. Miscellaneous 65

= Bottling and Packaging Radioactive Samples ... 65

Distribution of Uranium and Plutonium Standards. 66

Clean-Up Program 66

9. PERSONNEL AND ACTIVITIES 69

Personnel List 69

Talks 69

Committee Activities and Education 69

Publications 70

10. ACKNOWLEDGEMENTS 71

11. REFERENCES 72

vm
LIST OP FIGURES

FIGURE NO. PAGE

1. Automatic potentiometric titration apparatus

(mercury indicator electrode vs SCE) i\.

2. Titration of calcium and magnesium with

EGTA and EDTA 5

3. Thermogravimetric and differential Thermal

analysis apparatus 9

I4.. Thermogravimetric curve of calcium oxalate

monohydrate 10

5. Thermogravimetric curve of U_0n 11

6. Atomic absorption and flame emission

spectrophotometer 13

7. Modified recording flame spectrophotometer. . . 13

8. Resolution of the potassium doublet at

766.5 and 769.9 mp. l£

9. High sensitivity spectrophotometric cells ... 20

10. Variable light path spectrophotometric cell . . 27

11. Vacuum evolution apparatus for the determination of 2

, H

2 and N2 37

12. Calibration curve of Balzer-Bendix apparatus

for the determination of Op 39

13. Nitrogen apparatus for the alkali fusion and

hydrogen sweep method i_|_0

II4.. Sampling positions from bars of discaloy. . . . I4.7

15 • Correction of bias between cooperating

laboratories (results before and after

reevaluation for Fe and SiOp determination) . . 57

16. Deviations from average U~0p, for Homes takeSapin material in 1963-5* 60

17a. Packing details for Pu NBS standard

reference materials 67

17b. Packing details for U NBS standard

reference materials 68

ix
LIST OP TABLES

TABLE NO. PAGE

1. Precision of titrimetric methods as applied

to analysis in standard reference materials. . . 2

2. Cobalt by ferricyanaide-titration method .... 3

3. Comparison of the recovery of iron by two

separation methods 3

l±. Summary of gravimetric methods 6

5. Summary of analysis by flame spectrophotometry . 12

6. Determination of alkali metals in two standard

reference materials ll\.

7. The analysis of alkali metals and strontium in

cements 16

8. Precision of spectrophotometric methods as

applied to trace element analysis in standard

reference materials 18

9. Absorbance values of acetylacetone

"blanks" 22

10. Determination of beryllium in cartridge brass. . 23

11. Comparison of gravimetric and differential

results for several high temperature alloys. . . 2l\.

12. The function of absorbance of the reference

solution 25

13. Comparison of spectrophotometric values with

previous values 26

II4.. Spectrophotometric analysis of cartridge brass . 28

15 • Spectrophotometric analysis of white case irons. 28

16. Boron in high temperature alloys 29

17. Antimony in white cast iron by the Brilliant

Green method 30

18. Determination of Op in ingot iron (B-B

apparatus), temp. - 1650 °C, Ni - premelt,

collection time - l\. min 3^1- x
LIST OP TABLES (Cont'd)

TABLE NO. PAGE

19. Segregation of oxygen into two groups in

ingot iron samples 3^.

20. Scope of work in the analysis of ferrous base

materials i4.IL

21. Homogeneity study of white cast iron, per cent

composition lj.6

22. Distribution of carbon and sulfur in high

temperature alloy I4.8

23. Homogeneity and precision of trace components

in spectroscopic standard of high temperature

alloys of stainless steel 1+9

2I4.. Homogeneity and precision of analysis of

extruded Al brass (major components) 50

25. Homogeneity and precision of analysis of cast

extruded Al brass 51

26. Homogeneity and precision of analysis of

extruded and cast Al brass. Minor constituent

antimony 52

27. Homogeneity and precision of analysis of

extruded free-cutting brass (major components). 52

28. Homogeneity and precision of analysis of

extruded red brass (major components) 53

29. Homogeneity data for limestone 5K

30. Direct determination of carbon dioxide and

water (hydrogen) in feldspar. SS

31. Drying conditions for flint clay, 97a and

plastic clay, 98a SS

32. Reproducibility of the ignition loss of U'On

samples . . 62

33* Atom per cent corrected to June 1, I96I4. .... 65

XI
QUANTITATIVE SEPARATIONS

July 1961j. to June 1965

Edited by Oscar Menis

ABSTRACT

This is the first progress report of the Quantitative

Separations Section covering the 1965 fiscal period. The

report encompasses several areas of analytical chemistry

and discusses the activities of this section in relation to

the certification of values for standard reference materials.

These included a variety of ferrous, copper base alloys,

high temperature alloys, titanium base alloys, ceramic, clay,

rock and actinide materials

In the area of titrimetry, problems are discussed that

deal with the prior separations associated with the

determination of iron and cobalt in high temperature alloy.

Also, the application of complexometric titration with a potentiometric apparatus is described. In the gravimetric

studies, the application of thermogravimetric procedures to

establish a base line for weighing U3O3 is illustrated.

Current methods which were investigated for the determination

of aluminum in feldspar appear to give low results and a need

for a new approach is indicated. In another procedure, the

partial separation of hafnium from zirconium by an ion

exchange separation was achieved prior to a spectrographic

determination of this element. An atomic absorption

apparatus was installed and tests with the new instrument

and a modified flame spectrophotometer are presented. In

the spectrophotometric competence, high sensitivity and

high precision methods are discussed and applied. Boron

and beryllium were successfully determined at the

nanogram level of concentration. The differential spectrophotometric method was evaluated for the estimation of

high concentration of nickel by the modified dimethylglyoxime procedure. In addition, spectrophotometric

methods were applied to the determination of trace elements,

As, Be and P in brass B and Zr in cast iron, B in high

temperature alloy and nickel in steel and cast iron. An

initial investigation of the reaction of the brilliant

green reagent with pentavalent antimony indicated that this

method can be adapted for the determination of antimony in

white cast iron. In the area of gas evolution methods, a new apparatus is described in conjunction with a homogeneity

study of oxygen in ingot iron and other materials. Also, the

apparatus and procedure is presented for the determination of

nitrogen in materials containing refractory nitrides.

xii
Other aspects of the analysis of standard reference

materials are discussed from the standpoint of preparation

and conversion of the material to a suitable sample form,

homogeneity testing, stability, and the cooperative work

with outside laboratories. Special fields of analytical

interest involving the conclusion of umpire uranium analysis

are discussed.

Finally, the isotopic standards preparation program is

detailed for the uranium and plutonium materials.

Xlll
QUANTITATIVE SEPARATIONS

July 1961+ to June 1965

Edited by Oscar Menis

ABSTRACT

This is the first progress report of the Quantitative

Separations Section covering the 1965 fiscal period. The

report encompasses several areas of analytical chemistry

and discusses the activities of this section in relation to

the certification of values for standard reference materials.

These included a variety of ferrous, copper base alloys,

high temperature alloys, titanium base alloys, ceramic, clay,

rock and actinide materials

.

In the area of titrimetry, problems are discussed that

deal with the prior separations associated with the

determination of iron and cobalt in high temperature alloy.

Also, the application of complexometric titration with a potentiometric apparatus is described. In the gravimetric

studies, the application of the rmogravime trie procedures to

establish a base line for weighing UoOq is illustrated.

Current methods which were investigated for the determination

of aluminum in feldspar appear to give low results and a need

for a new approach is indicated. In another procedure, the

partial separation of hafnium from zirconium by an ion

exchange separation was achieved prior to a spectrographic

determination of this element. An atomic absorption

apparatus was installed and tests with the new instrument

and a modified flame spectrophotometer are presented. In

the spectrophotometric competence, high sensitivity and

high precision methods are discussed and applied. Boron

and beryllium were successfully determined at the

nanogram level of concentration. The differential spectrophotometric method was evaluated for the estimation of

high concentration of nickel by the modified dimethylglyoxime procedure. In addition, spectrophotometric

methods were applied to the determination of trace elements,

As, Be and P in brass B and Zr in cast iron, B in high

temperature alloy and nickel in steel and cast iron. An

initial investigation of the reaction of the brilliant

green reagent with pentavalent antimony indicated that this

method can be adapted for the determination of antimony in

white cast iron. In the area of gas evolution methods, a new apparatus is described in conjunction with a homogeneity

study of oxygen in ingot iron and other materials. Also, the

apparatus and procedure is presented for the determination of

nitrogen in materials containing refractory nitrides.

xii
Other aspects of the analysis of standard reference

materials are discussed from the standpoint of preparation

and conversion of the material to a suitable sample form,

homogeneity testing, stability, and the cooperative work

with outside laboratories. Special fields of analytical

interest involving the conclusion of umpire uranium analysis

are discussed.

Finally, the isotopic standards preparation program is

detailed for the uranium and plutonium materials

xm

1. TITRIMETRY

Titrime trie methods were used extensively as shown in

Table 1 to establish values for various components of

standard reference materials. While in many cases the precision and accuracy of the methods which are listed in this

table meet the requirement for the error limits set in the

NBS certificates, further reduction of errors is needed

especially at the microgram concentration levels. For that

purpose studies of potentiometric, spectrophotometric and

other techniques for the end point detection are under way.

A. Separation Problems

1. Determination of Cobalt in High Temperature Alloy

In addition, better methods for separation prior to the

final titration are needed as they are often the limiting

factors in attaining highest accuracy. An example of the

latter is the determination of cobalt in a high temperature

alloy (NBS II9I4.) by the ferricyanide titration method. The

critical part in the procedure is the gravimetric separation

step and the application of a correction for manganese. The

separation of cobalt by an alkaline precipitation involves

careful neutralization of the dissolved sample and oxidation

with bromate. In this case, to improve the current precision

as shown in Table 2, an ion exchange separation is being tried.

2

.

Determination of Iron in High Temperature Alloy

An example of another separation problem was the

determination of iron in a high temperature alloy. Iron was

determined in a synthetic solution of a high temperature

alloy by oxidimetric titration with a standard solution of

potassium dichromate in a procedure which involved two

different separation schemes. A synthetic solution was

prepared based on the following nominal composition of the

alloy in per cent: 5^-Fe, 25-Ni, l£-Cr, 2-Ti, 1-5-Mo,

0.7-Mn and 0.ij.-V. In one procedure the iron was separated

from the interfering elements by an ammonium hydroxide

and next by a sodium hydroxide precipitation. The second

procedure involved an H2S precipitation. In the first

procedure the results (shown in Table 3) f°r iron were found

to be low by 0.2 per cent while in the second, were O.L|. per

cent high.

Presently, extraction and ion exchange separation are

under study to improve the accuracy of this determination.

(R. Bell)
Table 1. Precision of titrimetric methods as applied to

analysis in standard reference materials.

Element Range Precision Oxidation Titration

Ferrous Alloys

Mn .1 - 0.9

.9 - 1.5

0.005

.01

(NH4 ) 2 S

2 0g + AgNO^ Na2As2 0^

S .01 - 0.1

.1 - 0.5

.002

.005

Combustion to S02 KI0,

5

Cr .01 - 5.0

5.0 - 18.00

.002

.02

(NH4 ) 2

S

2 0q Fe(NH4 ) 2S0

2|

V .005 - 0.1

.1 - 0.5

.001 HNO^

5

Sn .005 - o.io

.10 - 0.25

.002

.005

Separation

and NH^OH

with H

2

S KIO^

5

N .002 - 0.25

.05 - 0.15

.002

.002

Separation with Kjeldahl distillation

Acidimetric

Se .01 - 0.5 .002 Separated as metal KIO^

Copper Alloys

Sn .005 - 1.5

.001

.05

Separate with NH^OH

Fe carrier., Pb

KBrO,

5

Sb .005

reduction

001 Separate with NH^OH

Fe carrier reduced

with S and distilled

KBrO, or KMnO,

Fe

Co

50

5.0

High Temperature Alloy

.1 Separate with HpS

reduced with Snclp

.02 Separate with NaOH

precipitate after

oxidation with KBrOKgCr^

K

3

Fe(CN) 6

U 70 ~ 8o

Uranium (umpire analysis ) 0.05 Separate with R"2

S and Y^CvJdr,

cupferron extraction ' Jones Reductor
Table 2. Determination of cobalt by f erricyanidetitration method

Sample No,

Test

1

2

2,65

2.68

Average

Standard deviation

Cobalt {%)

2.63

2.64

2.69

2.65

2.67

2.64

2.66

0.02

Table 3. Comparison of the recovery of iron by two

separation methods

„

Separation method

Two NH4OH precipitations

and one NaOH precipitation

HpS precipitation

Iron (mg)

Present Found Diff erenc

537.4

555,2

237.9

257.4

251.2

259o3

536.8

554.0

237.8

258.7

252.4

260.6

- .6

-1.2

-0.1

+1.3

+1 2

+1.3

B. Complexometric Titration of Calcium and Magnesium

The titration studies are also being extended to

supplement the result by gravimetric methods for the

determination of calcium and magnesium in standard reference

materials of dolomite. In this case, the complexometric

titrations with a potentiometric mercury indicator electrode

system have been tested [1]. The apparatus is shown in

Figure 1. Typical titration curves are shown in Figure 2

for the complexones, ethylene glycol bis- (2 aminoethyl ether)

N, N' -tetraacetic acid, EGTA and ethylenediaminetetraacetic

acid, EDTA. As can be noted in Figure 2, the greater

stability of Ca-EGTA complex makes it feasible to titrate

calcium without the interference from magnesium. On the

other hand, with EDTA, Figure 2, both ions substantiate

the gravimetric values for the final certification of the

dolomite standard.

(K. M. Sappenfield)

3

\
Figure 1. Automatic potentiometric titration apparatus

(mercury indicator electrode vs SCE)
140

120

100

Mg

pH 10.0

pH 8.04

o .OI/iEGTA • .01^. EDTA

16 20 ML OF TITRAN -1 24 28 32 36 40

Figure 2. Titration of calcium and magnesium with EGTA

(pH checked as indicated). Titration of calcium

and magnesium with EDTA (pH 8.5 as adjusted

initially). General conditions: Instrument.,

figure 1; data j manually plotted; mercury indicator electrode vs SCE.
2 . GRAVIMETRY

While gravimetric procedures are considered as the

classical methods for obtaining accurate values, the "nonideal" condition when dealing with complex materials leads

to relative large errors due to such problems as

coprecipitation and absorption. Conditional solubility

constants for the solid phase formation may also differ

significantly from theoretical values derived in ideal

solutions. Finally, the stoichiometry of the final compound

will depend on the drying or ignition temperature and on the

rate at which equilibrium is reached. To control some of

these parameters and reduce errors, better separation

schemes, masking and demasking variables and thermogravimetric studies are being carried out. The current

applications are summarized in Table l±.

Table 4. Summary of gravimetric methods.

Element Range Precision Basic method

W)

Ferrous Alloys

Ni > .01 0.02 Dimethylglyoxime (DMG)

precipitation

Ni < .01 .003 Extraction of Fe

+^ with ether;

DMG precipitation

C 0.01-1.0 .004 Combustion^ absorbed and weighed

1.0 - 4.0 .02 as C02

Si 0.1 -1.0 .004 HC10.-H

2

S0k dehydration HF

volatilization

Copper Alloys

.0001 Separation of Sb, As and Sn; Cu

.01 by electrodeposition

.01 Separation by electrodeposition

.002 of Pb0

2

and lead molybdate

precipitation

.02 DMG precipitation (after Cu

electrodeposition)

.004 Electrolysis , CN complex

8-hydroxyquinoline

Cu 0.05

70.00

Pb 4

0.02

Ni .01

Al 2
Element Range

(ft)

65

Pr

+

ecision

] Si .05

Ca 2 .08

Mg .02 .01

P .02 .01

Na 2„5 - 6 .03

K 5. - 11 .05

Loss on

ignitior

.30

L .01

Fe 0.9

Al 1.

Ca 50.

Mg 0.4

Loss on 40.

ignition

Si 1.2

Ca 30.

co

2 40

Mg 21.5

Loss on 46.

ignition

Table 4. Summary of gravimetric methods (cont'd).

Basic method

Feldspar

Dehydrated with HCl, corrected

for soluble Si0o in Ro 0-, 2 2 3

Double oxalate precipitation

corrected for Ca in MgpPp07

Ammonium phosphate precipitation

corrected for Ca and Mn

Phosphomolybdate separation

Mg

2

P

2 ?

J. Lawrence Smith Na-K as

chlorides:3 K as Kn PtCl^- 2 o K as K

2 PtCl

6

Dry at 110 °Cj ignite at 1000 °C

Limestone

Si 5. .05 Dehydrated with HCl, corrected

for soluble SiOp in RpO^

,03 Evolution weighed as C0p

.02 Precipitate as FeS weighed as

Fe

2 3

.02 RpO^ corrected for Fe, P, Ti

and^Si

o 04 Double oxalate precipitation

corrected for Ca in MgpPpO,-,

.01 Ammonium phosphate corrected

for Mn and Ca

.03 Dry at 110 °C ; ignite at 1000 °C

Dolomite

.05 (Double dehydration HCl)

corrected photometrically

.05 Four oxalate precipitations

corrected for Ca in Mg2 P

2 7

.04 HCl evolution weighed as C0 2

.3 Ammonium phosphate precipitate

corrected for Mn and Ca

.02 Dry at 110 °Cj ignite at 1000 °C

7
A. Determination of Aluminum in Feldspar

One of the problem areas is the determination or

aluminum in feldspar. The aluminum in the samples was

determined gravimetrically using three different approaches.

In the first procedure the aluminum value of 70a, determined

by ammonium hydroxide precipitation which was corrected for

iron, silica, phosphorus, and titanium, was (about 0.15 to

0.10 per cent) lower than the cooperators . Aluminum was also

determined by the gravimetric 8 hydroxy- quinoline method [2].

The soluble aluminum quinolate in the filtrate was determined

photometrically with aluminon [3]. Finally, aluminum was

determined by precipitating with ammonium hydroxide after the

extraction of aluminum cupferrates with chloroform [l\.~\ . The values (based on the summation of the components) are

still a little low (0.1 to 0.2 per cent) and additional work

is under way to verify whether any loss could occur because

of an incomplete dissolution or due to any conditions

encountered in these procedures. To resolve these problems,

studies involving a new dissolution procedure, ion exchange

separation and a homogeneous precipitation technique are

under way.

(K. M. Sappenfield)

B. Stoichiometry of Uranium Oxide

Another problem dealing with the stoichiometric

composition of uranium oxide is being studied by a thermogravimetric procedure. The details of this evaluation are

described in the Uranium-Is o topic Standard Section.

(L. A. Machlan)

C

.

The rmogravime trie Analysis

A the rmogravime trie analyzer attachment for a differential thermal analyzer was received in May. The new instrument is shown in Figure 3. It is expected that this analyzer

will be used in such areas of study as: new weighing

compositions in gravimetric analysis and their range of

temperature stability, studying behavior of materials in

atmospheres of various gases, determination of purity and

thermal stability of analytical reagents, and automatic

gravimetric analysis.

8
Figure 3. Thermogravimetric and differential thermal

analysis apparatus.

Early work indicates it is possible to obtain a sensitivity of 5 U-g with a 100 mg sample load. The corrections for change in weight of a platinum boat on its ignition

from room temperature to 1050 C did not exceed 30 u-g- A

typical thermogravimetric curve for the decomposition of

calcium oxalate is presented in Figure [|_. It indicates a

relatively "noise" free performance at sensitivity of 0.1+ mg

per division. The curve, shown in Figure 5 for ignition

of NBS 950a- UoOo standard reference material in air at

sensitivity or 0.02 mg per division again, indicates that

a weight change of 5 u-g can be readily measured. In this case

with a 100 mg load a weight change of 5 parts per ten thousand

could be discerned.

(L. A. Machlan, E. R. Deardorff)

D. Preconcentration of Hafnium in Zirconium

The concentration of hafnium, in the range of I4.O to

[(.00 ppm, in the standard reference material of zirconium and

zircaloy was too low for a direct spectrographic measurement,

For that purpose hafnium was pre concentrated by an ion

exchange and gravimetric procedure. Hafnium was first

separated in a 3»5 M sulfuric acid solution from the bulk of

zirconium by ion exchange process. The eluate containing

the hafnium and part of the zirconium was then precipitated

with cupferron and next with mandelic acid. After an

ignition to the oxide it was ready for a spectrographic

analysis

(E. R. Deardorff)

9
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11
3. FLAME PHOTOMETRY

The flame photometric competence has the potentialities

of yielding accurate values for most of the elements present

in trace or relativity low concentration levels. Since one

deals in this process with solutions aspirated into a flame

source, the chemistry of these solutions plays a dominant

role in obtaining best values. Studies are, therefore, under

way to determine iron and aluminum in feldspar and calcium

and magnesium in dolomite involving solvent extraction, ion

exchange chromatography and radiation buffers. The precision

of the methods as used on the several materials analyzed

during the past year are given in Table 5«

Table 5. Summary of ana

spectrophotome

lyses

try.

by flame

Element

determined Range

(*)

Clay 97a and 98aa

Precision

+ {%) o

Li .075 - .12 1

Na .03 - o 08 10

K .5 - 1.0 1

Rb .002 - .005 20

Cs .004 - .00 10

Lime;stone la and Dol omite 88aa

Li .004 10

Na .02 - .04 15

K .14 - .25 3

Rb .002

N.D C D

20

Cs

Sr .009 - .14 10

fAll samples were dissolved in 5$ HClOi, + HF.

Not detected.

A. New Instrumentation

Further impetus to this work has been made possible by

improved instrumentation. Additional components for the two

flame photometry instruments were recently installed, adjusted

and tested. The instruments are shown in Figures 6 and 7.

12
Figure 6. Atomic absorption and flame emission spectrophotometer .

Figure 7. Modified recording flame spectrophotometer

,

13
With the Jarrel-Ash. instrument spectra of iron and strontium

were recorded and the optimum settings of slit widths, photomultiplier voltage, gain, burner position and fuel to oxygen

ratio were evaluated. The emission intensity of the strontium

line in the second order at 921 m\i was I4.O chart divisions

for" 3 ppm of Sr. Also, with the new scanning and recording

attachment to a modified. Be ckman Spectrophotometer the spectra

of sodium and potassium were recorded. The potassium doublet

at 766.5 and 769.9 #V- as shown in Figure 8 was resolved. It

is expected that by means of these instruments, the determination of trace elements in standard reference materials will be

expedited.

(K. M. Sappenfield and 0. Menis)

B. Determination of Alkali and Sr in Clays

In addition to the analytical results on alkali elements

for standard reference materials, Flint Clay 97a, andPlastic

Clay 98a reported in Table 6, strontium was determined in tha

Table 6. Determination of alkali metals in two

standard reference materials.

Alkali metal

determined ] Results

w

Precision

+ W

Flint Clay 97aa K

2 0.53 1

Na

2

• 05

5

10

Li

2

.12 1

Rb

2

.002 20

Cs 2

.004 10

Plas>ti c Clay 98aa K

2

1.06 1

Na

2

0.07

9

10

Li

2

.076

1

Rb2

.005 20

Cs

2

.004 10

lAll samples were dissolved in 5$ HCIO^ and

determined by flame photometry.

11+
3E£

t ~

..UJ-jr m

i:-i

I il

F f

J

[-?

mu.

Figure 8. Resolution of the potassium

doublet at 7&6.5 and- 769.9 mu.. Conditions: 1) instrument,

figure 7, 2) slit, 0.02 mm,

3) sensitivity at 15

arbitrary units.

1st curve scanning toward

long wavelength, 2nd curve

reverse scan.

15
presence of large concentrations of calcium. A non-aquous

50% acetone solution was used in this determination. In this

case, the sensitivity for the determination of strontium

was increased by a factor of two.

c - Determination of Alkali and Strontium in Cements

In cooperation with the Inorganic Building Materials Section, the alkalies and strontium oxide were determined in five Standard Reference Materials Cements by flame photometry Since only this laboratory determined lithium oxide and rubidium oxide, these values are not certified but are given for added information (see Table 7).

Table 7. The analysis of alkali metals and

strontium in cements.

Alkali metal

determined Standard ref erence material No. Pr'ecision

1011 1013 1014 1015 1016 W

Li2

0.002 0.001 0.005 0.004 0.012 1

SrO

Rb

2

• 101

.001

.08

9

.004

.25

2

.006,-

•°9

9

.005

.024

5

N.D. a

10

20

K

2 .28

1

• 52 6

1.022 .8 9o .038

1

Na

2 .09-l • 20

5 ^6 .165 .63^ 10

aNot detect*3d.

For this analysis a 0.2g sample is dissolved in perchloric acid, silicon is separated with repeated evaporations

with HP and finally, the sample is evaporated to dryness. The

residue is dissolved in 5 ml of perchloric acid and diluted

with water to a 100-ml volume. In this solution lithium and

rubidium were determined flame photometrically by the

standard addition method while strontium, sodium and potassium

from a calibration curve of synthetic standards.

D. Determination of Alkali Elements in Feldspar (70a)

A 0.2g sample was dissolved in perchloric-hydrofluoric

acids and silica was removed by repeated evaporation. The

solution was next evaporated to dryness and the residue

dissolved in perchloric acid with the final volume adjusted

to 100 ml of $% perchloric acid.

16
Rubidium and cesium in 70a were also determined flame

photometrically by dissolving the potassium chloroplatinate

from the gravimetric analysis of potassium in 100 ml of water

The effects of platinum upon the determination of these elements by flame photometry were tested and found to be nil.

The values for rubidium and cesium were the same as

obtained from the perchloric acid solution of the sample.

(K. M. Sappenfield)

17
]+. SPECTROPHOTOMETRY

During the past year progress in this field can be

conveniently divided into two categories: (1) high

sensitivity spectrophotometry and (2) high precision

spectrophotometry. In addition the general technique has been,

and is, finding numerous applications in the characterization

of standard reference materials as summarized in Table 8.

Table 8. Precision of spectrophotometry methods as

applied to trace element analysis in standard

reference materials.

Element Range Precision Basic method

~WT + {%) a Ferrous Alloys

Mo 0.005 -0.3 0.001 CNS complex extracted with butyl

0.3 - 1.5 acetate

Al .01 - 0.3 .005 Hg cathode separation; aluminon

Ti 0.02 - 0.2 .001 Cupferron precipitation; sodium

0.2 - 2.0 .01 peroxide

Co 0.001 - 0.1 .001 Nitroso-R salt reagent

0.1 - 0.0 .005

Nb 0.004 - 0.2 .001 Cupferron precipitation; anion

exchange; hydroquinone

Ta 0.04 - 0.08 .004 Separation as above; pyrogallol

N 0.001 - 0.1 .0005 Kjeldahl; Nessler's reagent

P 0.002 - 0.1 .002 Molybdenum blue complex

0.1 - 0.8 .01

Cu 0.002 - 0.1 .002 Citrate + NH^OH + EDTA; complexation^ diethyldithiocarbamate

Ni 20 .02 K^S^On oxidation; pH 13; dimethylglyoxime (20$ Ni by differential

method)

Copper Alloys

Ni 0.005 .001 Cu electrodeposited; Br? oxidation;

dimethylglyoxime

Mn 0.03 .002 Oxidized to MnO^ with KIO^

Fe 0.3 .005 NHlOH separation with Al carrier;

.01 .002 1, 10-phenanthroline

P 0.12 .005 Molybdenum blue complex

18
Table 8. Precision of spectrophotometric methods as

applied to trace element analysis in standard

reference materials (cont'd)

Element Range Precision Basic method

WT + W o

Limestone

Ti 0.04 - 0.05 .004 After Al separation; sodium

peroxide

Mn 0.15 - 0.20 .001 Oxidized to MnO^ with KI0^

Dolomite

Si 0.02 - 0.15 .005 Molybdenum blue complex

Al 0.2 - 0„3 .01 Aluminon reagent

Ti 0.01 - o 02 .002 Sulf osalicylic acid

P 0.005 - 0.01 .001 Molybdenum blue complex

Mn 0.02 - 0.03 .0002 Oxidized to MnO^ with KIO^

High Temperature Alloy

P 0.004 .0009 Molybdenum blue complex

0.02 .002

A. High Sensitivity Spectrophotometry

1 . Introduction

Development work in this area has centered around the

investigation of those color reactions which have shown

promise of being applicable at the submicrogram level.

Although the extension of spectrophotometric to these low

levels is inherently difficult, there are certain elements

for which sensitivities approaching a few nanograms can be

obtained. Boron, nickel, and beryllium have been shown to

belong in this group. Cobalt probably does also. The

success of such systems depends primarily on a successful

pre-concentration step which reduces the final volume of

the measured solution. Examination of these concentrates

through long path length cells then permits one, in favorable

instances, to obtain sensitivities down to the nanogram

level

19
2 . Cell Design

In practical applications a compromise will always have

to be made between cell volume and path length. One cannot

be increased indefinitely at the expense of the other because

of the many problems associated either with handling extremely

small volumes or with aligning the long path length cells

of very small cross-sectional areas.

A cell design which we have found quite adequate for our

present needs is shown in the photograph, Figure 9. These

cells were constructed in the NBS shop and the main bodies

Figure 9. High sensitivity spectrophotometric cells

20
are made of Teflon. They have a 10- cm light path and an

inside diameter of $.% mm. Total volume is therefore about

2.3 ml. The silica windows, which measure 1 x 11 mm, are

held firmly in place by pressure from a single "0" ring in

combination with the screw-on brass end cap. The tapered

openings allow these cells to be filled quite readily, the

sample being slowly poured down the sides of a hole.

3. Boron-Curcumin System

The first application of these cells to high sensitivity

spectrophotometry was to the boron- curcumin system. Although

the original color reaction dates back about 100 years, it

has received renewed interest in recent years because of the

great importance of boron analysis in the nuclear materials

field. The British in particular have spent a number of

years investigating and refining this procedure [5}6>7l»

The preliminary results of our work involving this system

indicate that a relative standard deviation of 5% can be

obtained in the 10-100 nanogram range. Additional work, however, need to be spent on separation procedures for certain

elements when present in large excess before any general

applications can be carried out at this level.

1+. Beryllium Acetylacetonate

a. Role of blank . A second highly sensitive system

which has recently been under investigation is the one formed

by the reaction between beryllium and acetylacetone

Strickland and co-workers described the initial work on this

system in the early 1950' s [8]» The procedure as developed

by them is applicable at the microgram level. In their paper,

they are quick to point out that, because of the magnitude

and variability of the reagent blanks, they could foresee

little hope of improving the sensitivity of their method

either by pre-concentration techniques or through use of

longer absorption cells. We have nevertheless re-examined

this system and have found that the absorbances of our

reagent "blanks" are at least an order of magnitude less than

theirs. Also our precision is better as is seen from Table 9.

Since the method depends upon the measurement of

absorbances in the ultraviolet portion of the spectrum,

extreme care must be taken to avoid contamination.

b

Determination of nanogram quantities of

beryllium with acetylacetonate . The analytical steps in the

present procedure are relatively simple. To a sample

containing 5-100 nanograms of beryllium, an adequate amount

of masking agent is added to complex interferences and the

resulting solution is adjusted to a pH of about 7.5 (in

practice anywhere in the range 6-10 has been found satis21
Table 9. Absorbance values of acetylacetone "blanks".

Procedures

Strickland'

s

method Current method

Measured Calculated

0.08 0.300 0.0060

0.08 0.312 0.0062

0.09 0.310 0.0062

0.08 0.320 0.0064

0.09 0.301 0.0060

0.06 0.290

were obtained

0.0058

aThese absorb ance values at a

50-fold increase in cone:entration over

Strickland '

s

results.

factory). Two ml of a 1% acetylacetone solution is added

and 15 minutes are allowed for complex formation; the

solution is then transferred to a small separatory funnel

and extracted with successive portions of 2, 1, and 1 ml

volumes of chloroform. The combined extracts are diluted

to volume in a 5>-ml volumetric flask, mixed, transferred to

separatory funnel, and then excess reagent is removed by two

15-second backwashes with 10-ml volumes of 0.1 N K0H. The

organic layer is drained off through a cotton plug to remove

droplets of water and then examined spectrophotometrically at

295 m|J.. The beryllium content of the sample is finally

determined by aid of a calibration curve.

Acetylacetone is not a specific reagent for beryllium

but fortunately the selectivity of the reaction can be vastly

improved through the use of masking agents. In practical

applications two alternatives exist in eliminating

interferences. Either one can separate the beryllium from

relatively large amounts of other interfering elements by an

electrolysis, batch extraction or the like and then complex

any residual interferences with a small amount of masking

agent, or else one can add a sufficient amount of complexing

agent initially to mask all interferences. The former

approach is necessary when analyzing matrices of a low beryl- lium concentration for example less than 0.1 ppm, while the

latter approach (direct masking) may be applicable at higher beryllium levels, especially if the matrix is not too complex.

c. Analysis of NBS samples . Using 1,2-diaminocyclo

hexanetetraacetic acid as a masking agent, three samples of NBS

cartridge brass have been analyzed. In order to test the procedure in the range of 5-100 nanograms of Be, the sample weights

varied from 5 to 100 milligrams. The means and standard deviation obtained on these three samples are shown in Table 10.

22
Table 10. Determination of b eryllium in

cartr idge brass.

Standard

reference Weight B eryllium (in nanograi

material No. Sample

(mg)

wt. beryllium Found Calculated

1100 5

b 0.0016 87 - 2

C 88

1101 iob 0.00055 57±3C

55

1102 ioob 0.00003^

3

29 ± 4

d h

, Calculated on the basis of previously reported values

No separation used.

,Four determinations.

Two determinations.

B. High Precision Spectrophotometry

1. Introduction

At its present stage of development differential

spectrophotometry has been shown capable of yielding

precisions of a few parts in ten thousand [9 1; using conventional spectrophotometry, one can achieve at best a

precision of approximately 0.2$.

The principle of the differential technique is straightforward and is not confined solely to spectrophotometry. The

difference in absorbance between the unknown and a suitably

chosen standard is measured. In its simplest form full-scale

reading adjustment is made to correspond not to the solvent,

as in ordinary spectrophotometry, but to a standard solution

of known concentration. There are, however, several possible

variations of this general method.

Differential spectrophotometry was first used by Kortum

[10] in the 1930' s. More recently, it has been advanced by

the work of Bastian [11] and Hiskey [12,15,1^]« In a

purely theoretical treatment Reilley and Crawford [15] have

also shown that the ultimate in precision can be obtained

by using two reference standards. Their method, however,

suffers from the disadvantage of giving a non-linear calibration curve.

Our current investigations in high precision spectrophotometry have thus far been concerned with relatively high

concentration and we have, therefore, been using only the

single standard technique. The possible application of a

23
differential method to the precise determination of nickel

and dysprosium is under investigation. Of the two, the

nickel system has been studied much more thoroughly and will,

therefore, be presented in some detail.

2 . Determination of High Concentration of Nickel

The general procedure for the determination of nickel is

based on the method described by Menis [16], except that

a differential technique was applied to samples containing

high concentration of this element. In this procedure the

colored nickel-dimethylglyoxime complex is developed at

pH 11 to 13 after oxidation with potassium persulfate.

Initial studies indicate that large amounts of nickel

can be determined in less time and with as much precision

and accuracy as in the gravimetric method. However, as shown in Table 11, there are still some differences that

need to be resolved.

Table 11. Comparison of gravimetric and differential

results for several high temperature alloys.

Difference

Standard NBS

reference Gravi- Differ- Differ- reference

material No. metric ential ence No. 1194

w (*) («

1193 28.38 28.36 -0.02 28.43

1194 24.06 24.10 + .04 —

1195 26.08 26.20 + .12 25.95

348 25.88 25.86 + .02 25.88

+0.05

- .13

.00

aVersus a standard reference solution of nickel.

The standard deviation calculated on twelve analyses of

NBS 1193 (see Table 12) using three different samples and

four different nickel concentrations in the reference

solution was 0.09$. The accuracy was best in the series of

samples measured versus a reference solution of A = 0.400

(see Table 12). These are the results of initial data and

variables are being investigated for improving the analyses.

A unique feature of this method is that similar alloys can

be compared spectrophotometrically for their nickel content.

This is demonstrated in Table 11 where the other three high

temperature alloys were compared with NBS 1194*

24
Table 12. The function of absorbance of the reference

solution.

0.005 0.2 O.k 0.6

Sample 1. 28.I4.5 28.23 28.37 28.k2

Sample 2. 28.25 28. 21j. 28.37 28.35

Sample 3. 28.29 28. V7 28.33 28.1+3

Other NBS standard materials analyzed for nickel by the differential spectrophotometry method were:

Standard

reference Certified Differential method

material No . Material value a Ni Diff.

(«

121c Crl8-Nil0 10.51 10.68 +0.17

(Ti-bearing)

121c Crl8-Nil0 10.51 10.52b +0.01

(Ti-bearing)

1175 White cast iron 2.97 2.99 +0.02

^Based on gravimetric results.

After hexone extraction.

In the case of the white cast iron, the iron to nickel

ratio was too great to keep the iron in solution under the

high pH conditions of the method. Therefore, most of the

iron was separated from the nickel by means of an anion

exchange column. Iron may also be the cause for the higher

results in 121c, since no separation was made in the first

determination.

(E. R. Deardorff and 0. Menis)

On the basis of the preceding discussion one might

conclude that an unlimited increase in precision can be

obtained by employing standard and unknown solutions of

sufficiently high absorbance. In practice this increase is

limited by two factors. In the first place full-scale

readings can be obtained with solutions having a high

absorbance only by using relatively wide slit widths. Under

these conditions the radiation is no longer monochromatic

and all solutes will deviate from Beer's law. The direction

of this deviation is such as to decrease the concentrational

sensitivity. Secondly, any stray radiation due either to

scattering or reflection from optical surfaces makes measurements with solutions of too high an absorbance essentially

25
useless. It may be concluded that for a system to be amenable

to differential spectrophotometry, it should (1) form readily

and have a high stability, (2) possess a low inherent

sensitivity and (3) have a wide characteristic absorption

band that is free from interferences.

(R. W. Burke)

C . General Spectrophotometry

1. Determination of Low Concentration of Nickel

The same nickel conditions as used for high precision

work can be used to determine small amounts of nickel by

direct spectrophotometry. Either an anion exchange column

or a methyl isobutyl ketone extraction can be used to

separate the iron from the nickel. The methyl isobutyl

ketone gave a much faster and cleaner separation than the

anion exchange column. Results using such a procedure are

contained in Table 13 • Preliminary investigation shows

that copper does not interfere with this procedure as much

as it does with other nickel-dimethylglyoxime methods.

Table 13. Comparison of spectrophotometry values

with previous values.

Standar d

reference Certified Ni Differmaterial No. Material value a determined ence

(%) [%)

l4d B.O.H. steel 0.041 0.041 0.000

l4e B.O.H. steel .053 .054 + .001

55e Ingot iron .038 .039 + .001

152 B.O.H. steel

(tin bearing)

.062 .065 + .003

152a B.0 o H. steel

(tin bearing)

.035^

.035

.057 —

1174 White cast iron .034 - .001

1174a white cast iron .036 - .001

fjBased on gravimetric results.

Not certified.

Future v/ork on this procedure will include determina- of the amount of iron that can be tolerated without separatic

checking the magnitude of the interferences such as copper.,

cobalt, and manganese; and use of a variable path cell, see

Figure 10, to improve the precision of the differential sp

photometric measurements. The linearity of this cell's micrometer scale will be evaluated.

26
Figure 10. Variable light path spectrophotometry cell.

2 . Determination of Trace Elements in Standard Reference

Materials

a. As, Be and P in brass.

b. B and Zr in cast iron.

c. B in high temperature alloy.

The values obtained spectrophotometrically for several

trace elements in cartridge brass are given in Table II4.

In Table 1$ results and the precision are given for boron

and zirconium in a number of white cast irons, and in

Table 16 for boron in high temperature alloy.

27
Table 14.

Standard

reference

material No.

C1100

1101

CHOI

1102

C1102*

Spectrophotometry analysis of cartridge

brass.

Phosphor-us

weight {%)

0.010

Q

o.ooi86

0.0020

0.0047

0.0046

Rel. Std. Deviation 3$

Arsenic

weight

0.020

2

0.008

q

0.009Q

0.004,-

5

0.004cD

Beryllium

weight {%)

0.0015

g

0.00055

0.00054q

0.00003^

0.0003

1%

3

Phosphorus determined on the yellow phosphovanadomolybdate

^complex.

Arsenic separated as elemental As by reduction with hypophosphite and determined as the molybdenum blue complex.

, Beryllium determined as the acetylacetonate.

Based on three determinations for P and As; based on two

determinations for Be.

Based on three determinations for P; based on two determinations for As and Be.

Table 15. Sped

cast

:rophotometric ana

iron.

lysis of whit

Standard

reference

material No. Boron Zirconium

weight {%) weight {%)

1174° 0.039 0.011

1174ad 0.043 0.020

1175° 0.0050 0.039

H75ac 0.0043 0.029

1176e 0.0008

1177f 0.025

1178 d 0.114 0.014

H79f 0.051 —

H80e 0.0020 _—_

28
Table 15

Spect

cast

;rophotometric

iron (cont ' d)

analy;sis of whit

Standard

reference

material No. Boron

weight {%)

Zirconium

weight ( a/o)

Il82 d 0.0091 0.0097

1183 d

0.057 0.125

Rel. Std. Devi ation 10$ b°/o

Determined as curcumin complex following separation as the

, methy borate ester.

Pyrocatechol violet employed as the chromogenic reagent.

Based on two determinations for B and three determinations

.for Zr.

Based on two determinations for B and two determinations

e for Zr.

f Based on three determinations for B.

Based on two determinations for B.

Table 16. Spectrophotometry analysis for boron in

high temperature alloys.

Standard

reference

material No . Boron

weight {%)

348b 0.029

1190b O.093

1193b 0.023

1194b 0.088

1195c 0.0042

1203b 0.0062

Rel. Std. Deviation 3^

Boron determined as the curcumin complex

following separation as the methyl borate

, ester

Based on three determinations.

c Based on five determinations.

' 29
3. Determination of Antimony by the Brilliant Green

Procedure

One analysis found especially difficult in studies

performed during the past year has been the determination of

antimony in cast iron. After attempts by other competences

were unsuccessful, recently, by means of the spectrophotometry,

the problem now appears to be resolved. Some representative

results are shown in Table 17

•

Table 17. Spectrophotometric analysis for antimony

in white cast iron by the Brilliant Green

method.

Standard

reference

material No . Antimony

weight {%)

117 ^a,b

.2:

J

ii7^ab :.2:j

1175

b 0.0192

1175ab 0.0205

1176b

0.

1177b 0.200

Rel. Std. Deviation

Typical composition of a white ire.::

C, 2-4: ; Mn, 0.5-1.52'; P, 0.01-0.8& S,

0.02-0. 2$ ; and Si, 0.5-3.5^ ^lus residuals

including: Cu, Ni, Or, V3 Ilo, Ti, As, Sb,

,N, Sn, Co, Te, B, 3i, Zr , Pb, and Al.

Based on three determinations.

Briefly, the procedure adopted is as follows : The sample

is dissolved in concentrated hydrochloric acid via the sealedtube technique [17] • By so doing, any possible loss of

antimony either as stibine or SbGl^ is prevented.

solution is removed from the tube and diluted to a convenien:

volume with 1:1 HC1. A suitable aliquot is taken for analysis

and the Sb J is oxidized to Sb ^ with sodium nitrite. The

sample is then diluted fourfold with a saturated solurion of

sodium pyrophosphate (P. 0- ' is used to mask iron interfere::

M- ( +5 An excess of Brilliant Green solution is added, the Sb

complex is extracted into toluene, and the extract is examined

30
spectrophotometrically at 650 mu. . The antimony content is

finally determined by aid of a calibration curve. Once the

sample is in solution, a single determination can easily be

made in five minutes

(R. W. Burke)

l±. Analysis of Trace Quantities of Manganese and

Silicon in Titanium Alloys

Other analyses which have caused some concern during the

past year have been the determination of manganese and silicon

in titanium alloys. During this period the sensitivity of

the periodate method for manganese in these materials has been

extended from $0 ppm to 5 ppm. At this lower level a number

of outside laboratories have experienced considerable

difficulty in obtaining reliable results. This difficulty

has now been traced to the presence of organic compounds in

the de-ionized water they had employed. By using redistilled

water it was demonstrated that a high degree of precision and

accuracy can be obtained with this procedure for the

determination of manganese at these lower levels.

The ASTM procedure for determining silicon in titanium

alloys by the molybdenum blue method indicated no interference

from tin [18 ] . However, in NBS 176, a new titanium standard

metallic tin remained undissolved in the dissolution step.

The metallic tin reduced the ammonium molybdate reagent and

produced a blue color even in the blank solutions. When the

sample was oxidized with a few drops of hydrogen peroxide,

however, the tin dissolved and did not interfere in the

silicon determination.

(E. R. Deardorff)

Also a second method for determining silicon in titanium

was also employed. In this procedure the silicomolybdate

complex is extracted with butyl alcohol and then the

heteropoly blue comples is formed directly in the alcohol

extract. By carrying out this extraction step the silicon

was separated from interfering elements and consequently the

accuracy of the determination was substantially improved.

(R. Bell and E. R. Deardorff)

The precision of spectrophotometric methods as applied

to trace element analysis during this period is demonstrated

by the results shown in Table 8. As can be seen, suitable

methods are presently used for a large number of elements

in a variety of materials

31
5. Conclusion

Most of the difficulties encountered in spectrophotometry

are still due to the complex chemical nature of the sample.

The most difficult problems have to do with separation and

preconcentration of the desired constituent and with the

removal of interfering substances. In the future it is hoped

greater use can be made of masking phenomena, extractions

and chromatographic separations in an attempt to increase

the selectivity of both high sensitivity and high precision

studies

.

(R. W. Burke and 0. Menis)

32
5. GASES IN METALS

The efforts in the area of analysis of metals for

gaseous constituents during the past year centered around the

determination of oxygen in ferrous and titanium alloys. A

major phase of this work dealt with the homogeneity testing

of various metal samples that are to be certified as to the

content of the gaseous elements, 0~ , Np and PL,

A. Determination of Gases in Ferrous Alloys

1. Types of Materials

Pour ferrous alloys are now being investigated for

possible use as standards containing certified amounts of

gaseous components. The major study at this time dealt with

the determination of the oxygen content. The four alloys

tested are as follows:

(1) Ingot Iron obtained from the Armco Steel Corp.,

1/L|_" diameter, 12-ft lengths, about 225 rods.

(2) [j_31 Stainless Steel obtained from the Allegheny

Ludlum Steel Corp., 5/16" diameter, 12-ft

lengths, about 170 rods.

(3) Vacuum Melted Steel obtained from the United

States Steel Corp., l/lj." diameter, 2-ft

lengths , 5 lots

(I4.) Valve Steel 21-lj. N obtained from the Allegheny

Ludlum Steel Corp., I/I4." diameter, 10-12 ft

long, 250 rods.

All of the above materials were procured through the

services of a representative of the AISI

The ingot iron, I4.3I stainless steel and the vacuum

melted steel have been analyzed in this laboratory and

samples of each of these materials have been sent out to

cooperating laboratories, the results of which have been

received and tabulated.

2

Evaluation of Results

After careful consideration of the results obtained in

this section and outside laboratories it was decided that

additional tests would be desirable. The new testing program

(after consultation with the National Bureau of Standards

Statistical Engineering Laboratory) was designed to evaluate

the errors due to the inhomogeneity of the material and that

due to the method. For that purpose, a sample of some

33
40 rods out of each, lot of material as against -the . original

12 rods sample is now under way. Pour samples are to be

taken from a single 12-inch rod in which A and C are opposite

ends and B and B' are adjacent middle sections of the rod.

These tests are being carried out in a new apparatus which

is described in the Apparatus Section. About 1/4 of this

reevaluation program of the analysis for oxygen is now

completed for the samples of ingot iron. The data from

this first test summarized in Tables 18 and 19 indicate

that the material could be grouped into two lots containing

525 + 10 PPm and hlS ± 10 ppm oxygen respectively.

Table 18. Determination of oxygen in ingot iron by

CO-Infrared measurement a Standard

reference Oxygs5n Standard

Date material No. Found Average Deviation

(ppm) (ppm) (%) a 6/4 40A-1

40B-1

40B'-1

40C-1

525

511

510

539

521.3 2.6

6/4 39A-1

39B-1

39B--1

39C-1

475

474

477

475

475.3 .3

6/4 32A-1

32B-1

32B'-1

32C-1

509

515

516

521

515.3 1.0

6/4 12A3

12B-3

12B'-3

120-3

479

475

471

476

475.3 .7

6/4 31A-1

31B-1

31B'-1

31C-1

537

476

528

536

534.8 .9

6/9 11A-1

11B-1

HB'-l

12C-1

486

476

479

515

489.0

34
Table 18. Determination of oxygen in ingot iron by

CO-Infrared measurement ( cont'd ). a Standard

reference Oxygen Standard

Date material No. Found Average Deviation

(ppm) (ppm) W

6/9 30A-1

30B-1

30B'-1

30C-1

487

483

483

481

483.5 .5

6/9 29A-1

29B-1

29B'-1

29C-1

487

485

501

483

489.0 1.7

6/9 28A

28B-1

28B '-1

28C-1

484

478

489

483

483.5 .9

6/9 10A-3

10B-3

lOB'-l

10C-3

553

534

520

532

534.8 2.6

Temperature at 1650 C, Ni-premelt, collection time,

four minutes.

Table 19. Segragation of oxygen into two groups

in ingot iron samples.

Standard reference Standard

material No. Oxygen (average ) deviation

(ppm) {%) o 39, 12, 11, 30, 482.6 2.0

29, 28

40, 32, 31, 10 526.5 2.4

The estimate of precision as shown by the relative standard

deviation (RSD) values in Table 18 is better than previous

data obtained with the NRC instrument. Pinal evaluation

35
of the significance of these values will be made on

completion of the tests. A similar study will also be

done on the I4.3I stainless steel and the vacuum melted steel

in order to get additional information of homogeneity, as well

as obtaining a more accurate value for oxygen content of the

materials

.

The work on the sample of valve steel was interrupted

because of the large error in measuring the oxygen in the

presence of the very high concentration of nitrogen. However,

it is planned to attack the problem with the new apparatus

which eliminates this difficulty.

B. Determination of Gases in Titanium and Titanium Alloys

Four titanium alloys have been acquired through the

services of Mr. S. Vigo of the U. S. Army Material Research

Agency to be used as standards for gas content.

The materials are as follows:

(1) Unalloyed Titanium obtained from Republic Steel

Corp., 511 bars I4." long by 1/2" diameter.

(2) 6 Al-l+V - Titanium Alloy obtained from

Titanium Metals Corp., 287 bars, 0. [(.35-inch

diameter and 7-5 inches long.

(3) &f° Mn - Titanium alloy obtained from Mallory

Sharon Me tals Corp., 580 bars, 5/8" diameter

and I4. inches long.

(1+) Titanium Alloy (Cr 10$, V 13% and Al 3%),

B120VCA, obtained from Crucible Steel Co. of

America, 350 bars, 0.1^.75- inch diameter a^d

I4. inches long.

The preliminary analysis of the unalloyed, 8% Mn

alloy and the AI-I4.V alloy have been completed in this

laboratory using a platinum bath, method and the results

collected.

Samples of the above material have been sent out to

cooperating laboratories and results from most of them

have been received. We are now in the process of collecting

and correlating these results for a statistical treatmenr

.

Considerable difficulty in obtaining reproducible

results with the B120VCA alloy has been also encountered

and a method for analyzing this material with some degree

of certainty is now being investigated. For that purpose

a tin flux and tin bath method is being substituted for

the platinum flux.

36
C . Apparatus

Up to May 1965 only one vacuum fusion apparatus,

NRC 912, was available for the analysis of gases in metals.

In this apparatus the metal sample is melted in a graphite crucible and the gases collected and measured using

a calibrated McLeod gage. The gases are then separated by

means of a differential freezing technique, and the amounts

of gas in the metals determined by a constant volume pressure

measurement technique.

In May an additional apparatus manufactured by the

Bendix-Balzer Corp., Exhalograph EA-1 was received and is

shown in Figure 11. In this apparatus the sample is again

Figure 11. Vacuum evolution apparatus for the determination of

2

, Hp and N~ . 37
melted under vacuum in a graphite crucible and the gases

given off are collected. The method of measuring these gases,

CO (from the reaction of oxygen with carbon), Np and Hp

differs, however, and is as follows:

(1) The CO is analyzed with an infra-red analysis

apparatus

.

(2) The Hp is analyzed in a thermal conductivity cell.

(3) The nitrogen is analyzed using a pressure difference

method.

The particular advantages of this apparatus are that

the CO can be determined by a direct method and not by a pressure difference, and also the extreme rapidity with

which the samples may be analyzed. For example, recently,

with this apparatus it was possible to analyze I4.O samples

of ingot iron in one day. To analyze this number of samples

by the use of the NRC 912, requires 2 or 3 weeks under

ideal conditions. It is hoped, therefore, to use this

apparatus extensively, especially in the survey of material

for homogeneity.

It is also possible to calibrate this apparatus using

the pure gases CO, Hp, Np admitted to the apparatus by

means of a special calibration block. A typical calibration

curve for the addition of CO gas under STP condition is

shown in Figure 12. This feature is especially desirable

as a check whether gettering is taking place in the apparatus,

as may happen with certain metals. This checking is

accomplished by adding to the furnace section the same

amounts of gases which are collected from a metal sample and

then repeating the analysis to see whether complete recovery

is attained.

(J. T. Sterling, F. Palumbo)

D. Determination of Nitrogen in Ferrous Alloys by Alkaline

Fusion

1 . Introduction

Two methods, the vacuum fusion and the Kjeldahl, have

been extensively used to determine nitrogen in metals. The

first method requires complicated and fairly expensive

equipment and is not readily applicable for handling large

number of samples. Although the Kjeldahl method is used

extensively it has been shown to fail when acid resistant

nitrides such as those of silicon and boron are present [19].

38
40 50 60

INFRARED, CO, IN ARBITRARY R UNITS

Figure 12. Calibration curve of the infra-red absorbance

apparatus for the determination of 0^.

(smooth line manufacturer's initial calibration)

When acid resistant nitrides are present, an alkaline

fusion method is best suited. Bennett [20] fused samples

with an oxidizing mixture consisting of sodium carbonate,

potassium carbonate and potassium chromate. The volume of

the resulting nitrogen was measured in a nitrometer. Karp

et al [19] fused the alloy in an atmosphere of hydrogen with

sodium hydroxide containing a little sodium carbonate. The

resulting ammonia was absorbed and determined photometrically.

The method suggested by Karp et al will be used to

determine nitrogen in the ferrous alloys issued as standard

reference materials. These values of nitrogen will be

compared with those found by other methods.

39
Apparatus and Method

The photograph

determination of nit

et al [19]. The ess

of nickel tubing whi

furnace. The ends o by means of wrapped

The evolved ammonia

glass washing bottle

from the apparatus b

in Figure 13 shows the apparatus for the

rogen by the method suggested by Karp

ential part of the apparatus consists

ch is heated to 950°C by a split tube

f the nickel tubing are cooled by water

copper coils soldered to the nickel tube.

is absorbed in water contained in the

Argon is used to remove the oxygen

efore the hydrogen is introduced.

^

I

i*

Figure 13 . Apparatus for the alkali fusion and hydrogen

sweep method for the determination of nitrogen

3. Initial Results on Nitride Determination

In the first tests with NBS 125a, results comparable

to those reported by Karp et al [19] were obtained.

These are almost by a factor of two greater than the certified

value. The application of this method to check the presence

of refractory nitrides in standard reference materials should

prove, therefore, of great value.

(B. B. Bendigo)

1+0
6. ASPECTS OF ANALYSIS ASSOCIATED WITH

STANDARD REFERENCE MATERIALS

A. Introduction

Other aspects of the work of this section relating to

the analysis of standard reference materials by one of the

competences described previously, deal with the following

areas: assistance in procurement of the material, conversion

of the material to a suitable sample form, homogeneity testing,

selecting and sending samples to cooperating outside

laboratories and, finally, evaluating the results of these

laboratories and incorporating their values in the

certification. Most of these activities have now been

assumed by the Office of Standard Reference Materials.

Some of the problems and data relating to this work

are described in this section of the report. It deals with

the general type of materials of ferrous, non-ferrous,

ceramics, limestones, ores, uranium and plutonium. This

group represents approximately 25 standard reference

samples of the 540 issued by the Office of Standard Reference

Materials . The methods of analysis described in the section dealing

with various competences, are selected or designed to give

the best obtainable results and depend upon the matrix of

the material. In some instances, more than one procedure

is employed for an element as a cross-check on both the

precision and accuracy of the composition.

The following table, Table 20, gives information on 18

standard iron-base alloys that were either prepared, analyzed

and certified since January 1964 or are in the process of

analysis .

Table 20. Scope of work in the analysis of ferrous

base materials. a

Standard Number of

reference Number of Elements determinamaterial No Type cooperat;ors certified tions (NBS)

346 Valve steel 7 C,Mn,P,S,Si, 119

Cu3 Ni,Cr.,V3 N

27e Iron ore 15 Fe.P^SiOg 40

131a Low carbon

steel

9 C " 23

l4e B.O.H., 0.8

carbon steel

5 C,Mn,P,S,Si, 88

Cu,Ni,Cr,V,Mo

41
Table 20.

Standard

reference

material No.

Scope of work in the analysis of ferrous

base materials (cont'd) . Number of

Number of Elements determinaType cooperators certified tions (NBS )

152a B.O.H., 0.4 6

carbon steel,

tin bearing

12h B.O.H., 0.4 5

carbon steel

1176-1185 Cast irons 5

1174~1174a Cast irons

1175-1175a Cast irons

C 5 Mn,P,S 5 Si 5 53

Cu,Ni,Cr,V,Mo,

Sn

C,Mn,P,S,Si, 46

Cu,Ni,Cr,V,Mo,

N

C,Mn,P,S,Si, 335

Cu^Ni.Cr^V^Mo,

Ti,Sn,Co,Al,

Pb,Bi,As

C,Mn,P,S,Si, 86

Cu,Ni,Cr,V,Mo,

Ti,Sn,Co,Al

C,Mn 5 P,,S,Si, 62

Cu,Ni,Cr,V,Mo,

Ti, Sn,Co,Al

lAll work completed except for sample 152a.

In addition to the samples listed above, the laboratory

completed the analysis of two additional samples.

Standard sample 19g, B.O.H., 0.2$ carbon steel is

specially noted because it provides a group of residual

elements that are becoming of significant interest and

importance to the steel industry. The residuals and their

certified values are given.

certified values are given as follows:

Elements Per cent Elements Per cent

Cu 0.093 Nb 0.026

Ni 0.066 Sn 0.008

Cr 0.374 Al 0.031

V 0.012 Ti 0.027

Mo 0.013 Co 0.012

42
The addition of standard sample 339 to the list of standard

reference materials represents the Bureau' s first attempt at

providing a standard sample certified for selenium. This

new standard is a stainless steel containing 17 per cent

chromium, 9 per cent nickel and 0.25 per cent selenium.

Detailed procedures for the analysis of these types of

materials are being published in NBS-260 series.

B. Preparation and Conversion of the Material to a Suitable

Sample Form

The preparation of the standard reference materials for

use in analyses is important and without which the highest

degree of accuracy in analysis cannot be attained. The

procedures used for a variety of materials such as ferrous,

non-ferrous, ceramics, clays, rocks, actinide elements are

briefly outlined here. In the subsequent sections are

described the analytical tests employed to establish the

homogeneity of these preparations, and the work associated

with the cooperators.

1. Steel Samples

For the preparation of standard steel samples, the

material which is furnished to NBS by the steel industry, is

in the form of round bars about 6 inches in diameter and

36 inches in length and weigh approximately 200 pounds each.

Six to twelve bars are generally used for one standard and

must be from the same heat and sufficiently homogeneous so

that the entire lot can be issued under one certificate of

analysis. The outside surface is removed with a heavy-duty

lathe and discarded. The bars are then turned into nicked

"chips" with a special high-speed tool having a serrated

cutting edge. The serrations on the cutting face of the tool

control the length of the chips, which are ordinarily I/I4. to

3/I4- inches in length, the other dimensions being controlled

by the speed of the lathe and the feed. For ordinary steels,

the lathe speed is approximately 16 rpm and the depth of cut

is 0.011 inch. These may vary, however, depending upon the

cutting characteristics of the material.

Cutting is discontinued when the core section

approximates l-l/lj. inches. Because it is rarely possible

to produce directly the form of chips desired, it is

necessary to crush or grind the cuttings in a chilled-iron,

Lawrence-type crusher, in order to obtain material of suitable

particle size. The material is next sifted and the propersized portion, usually that between a No. 16 mesh (1.19 mm

sieve opening) and a No . l|_0 mesh (1^.20 micron sieve opening),

is retained for use as the standard sample. The entire

k3
sample is then m-ixed in a large cone-shaped mixer for 1 or

2 hours

.

The particles of samples of the metal standards must be

comparatively small and be more or less uniform in size,

because as is generally well-known the composition may vary

with "chip" or particle size.

On a recent 7 bar lot of ll+e (B.O.H. , 0.8 per cent

carbon steel), the following summary shows the recovery of

the finished material from the original bar stock.

Standard Total Final chip

reference Number Size weight sample Number

materials No . of bars ( inches ) (lbs) (lbs) of units

l4e 7 6"x36" 2075 1761 ^750

The discarded material consisted of the following:

Cores Dust and fines Miscellaneous

(Ids) (lbs) (^s)

100 108 106

2

.

Cast Iron

To prevent undue segregation, cast irons for use in the

preparation of standard samples are cast in the form of

hollow cylinders approximately 30 inches in length, 12 inches

outside diameter with a wall thickness of about 2 inches.

The cylinders are machined using a multiple tool consisting

of l\. ordinary turning tools clamped together.

The machined material is first sifted to remove the fine

particles of iron and free graphite. It is then mixed in a large cone-shaped mixer for 1 hour through which a strong

current of air is passed to remove any free graphite. The

mixing gives rise to a certain amount of fine material and the

mixed sample is, therefore, again sifted to obtain the desired

particle size which is the portion that passes a No. 16 mesh

sieve and remains on a No. 35 mesh sieve.

3. Spectrographic Samples

Spectrographic samples for chemical analyses vary in

types, sizes and composition and are sampled accordingly.

1*1*-
a. White cast iron . These alloys are prepared from

l-l/L|.-inch square and ^/l^-inch. thick solid sections by

breaking brittle segments cut from the certified portion

of the samples, in a hardened iron mortar with an iron pestle.

The material is then sized to pass through a No . IJ4. sieve.

b. Carbon and alloy steels . These alloys are

prepared in a variety of sizes C7/32 inch in diameter and

I4. inches long; 1/2 inch in diameter and 2 inches long; and

1-1/1+ inch in diameter and 1/1+ inch thick) and are sampled

either by milling the cross section of the accepted material

or by lathe-cutting to the desired particle size. Generally,

for those samples whose diameters are less than 1 inch, the

former technique is used, while the latter procedure is

followed for samples whose diameters are greater than 1 inch.

c. Copper-base alloys . Similar processes and

preparation tasks were carried out for copper-base and other

non-ferrous alloys. The preparation of the spectrochemical

standards for which chemical analyses were performed during

the past year is described in the NBS 260-2 [21]. Sampling

was carried out on rods or bars by cutting with a milling

machine or drilling cores at different positions.

I4.. Limestone and Dolomite

Limestone and dolomite materials were ground with an air

reductionizer and screened in a classifier. The final sample

was passed through a 200-mesh sieve.

5. Rocks and Ceramics

These materials are crushed, ground and screened through

a 100-mesh sieve. The materials are then mixed in a

porcelain-lined conic mixer.

6

.

Actinide Elements

The actinide elements, especially uranium-235 and -233*

Plutonium metal or compounds such as oxides or sulfates are

handled in hoods or glove boxes because of their high toxicity

from alpha emission.

C . Homogeneity Studies

A major factor in characterizing standard reference

materials involves the establishment of the homogeneity of the

sample before it is analyzed for final certification.

Depending on the type of material and method of preparation,

behavior of a given element during the process of preparation,

and the precision of the method used in determining the

element, considerable time and effort is expended on this

US
type of investigation. During the past year, homogeneity

tests were performed on ferrous-base and copper-base

spectrographic standards, and other ceramic or rock materials.

In the following sections general characteristics of the

materials and the evaluation of their homogeneity are

described.

1 . Ferrous-Base Materials

a. White cast iron standards . Supplementing the

previously analyzed and certified white cast irons (II76-II83)

are two additional white irons 1174 > 1174a and 1175 > 1175a.

These standards were developed as replacements for the limited

supply of the eight standards (II76-II83) prepared previously

and are to serve the long-term need for these types of alloys.

Preliminary homogeneity testing for carbon, phosphorus,

sulfur and silicon was considered necessary because of the

complexity of the metallurgical structure of white iron. The

table shows the data obtained for the 4 elements. The spread

of values falls within the error limits of these determinations indicating optimum homogeneity.

Table 21. Homogeneity study of white cast iron,

per cent composition.

Standard

reference

material No. £ P S_ Si

1174 3.50, 3.51 0.227, .233 0.153, .155 0.288, .292

1174a 3.46, 3.45 0.288, .230 0.157, .156 0.286, .289

1175 1.98, 1.97 0.592, .591 0.016, .017 3.47, 3.46

2.04, 2.00

1175a 2.04, 2.00 0.600, .602 0.017, .017 3.44, 3.44

1.99, 1.99

In addition to the values obtained above, homogeneity

testing by spectroscopy indicated the white iron material was

sufficiently homogeneous to be used as spectrographic

standards

.

Other data obtained by this section includes values (by

the general methods outlined in the section of this report

describing the competences) for the following elements:

manganese, copper, nickel, chromium, vanadium, molybdenum,

titanium, tin, arsenic, cobalt, bismuth, lead and aluminum.

46
b. Maraging steels . The maraging nickel steels are

a group of relatively new, very low carbon iron-nickel alloys

that exhibit ultra-high strength yet possess exceptionally

high ductility and toughness. Because of these desirable

physical characteristics they are becoming of considerable

commercial interest and importance. Two alloys, NBS 1155 and

1156, have been analyzed for carbon., phosphorus, sulfur,

nickel, molybdenum and titanium to establish homogeneity.

Whether or not the material can be used for standard samples

will depend upon additional data being supplied by spectrochemi c al analys e s

c. High- temperature alloys . Three (3) nickel

chromium- iron alloys (NBS 1193* H9I4. and 1195) referred to

as Discaloys, have been analyzed for carbon and sulfur for

homogeneity prior to their analysis at NBS and before

being sent to selected laboratories for cooperative

analysis. The carbon content ranges from 0.007 (1195)

to 0.028 (1193) per cents and the sulfur ranges from

O.OII4. (1195) to O.O83 (H91+) per cents, in these three

materials

Of interest, are data that were obtained in

connection with homogeneity studies during the cutting

operation of standard sample 19g, 0.2 per cent carbon steel.

Samples were taken from different positions on two bars and

analyzed for carbon and sulfur.

The figures below represent cross-sections of each of

two bars and show the distribution and relative values

obtained for the two elements at three positions. From the

data in Table 22, it was concluded that the variations were

not significant enough for rejection; hence, the material

from the two bars was processed for standard sample use.

BARS

Figure 11].. Sampling positions from bars of discaloy
Table 22. Distribution of carbon and sulfur

in high temperature alloy.

Bar Position Distribution

1

2

5

1

2

5

bon (%) Sulfur (%

0.224

0.225

0.051

0.051

.228 .052

.236 .054

.054

.252 .052

.229

.227

.052

.240

.242

.055

After final processing of the material, the final certified

values for the two elements, carbon and sulfur, are 0.223

per cent and 0.033 per cent, respectively.

In a stainless steel high temperature alloy trace

elements, Ti, Zr, Nb and Ta were also determined and are

summarized in Table 23.

kQ
Table 23. Homogeneity and precision of trace components

in spectroscopic standard of high temperature

alloys of stainless steel.

Sample Set Weight Distribution

(g) Ti Zr

a Nbb

{*)

Tab

1152 1 5

10

0.117

.116

0.026

.029

0.203

.201

0.080

.083

2 25

30

Average:

Standard

Deviation:

.124

.116

0.118

0.004

.030

.030

0.020g

0.002

.202a .o88a

0.202

0.001

0.0837

0.0044

1154 1 5

10

0.473

.465

0.020

.021

0.260

.259

0.043

.044

2 10

15

.487

.486

.020

.020

.251a

.251

.044

.045

Average:

Standard

Deviation:

0.478

0.01

0.0202

0.0005

0.255

0.005

0.044

0.0008

^Gravimetric values.

Spectrophotometric values.

(R. K. Bell)

2 . Copper Base Materials

The compositions of seven principle copper-base alloys:

cartridge, free-cutting, naval red and aluminum brass;

gilding metal and commercial bronze of nominal, high and low

compositions were tested for homogeneity.

Some of the homogeneity data for these materials,

representing chill-cast and extruded standard reference

materials are given in the following tables: in Table 24

data on the distribution of copper, aluminum and phosphorus

in aluminum brass; in Table 25 data for arsenic by two

methods, in Table 26 data for antimony; and, data in

Tables 27 and 28 on the distribution of copper and phosphorus

in free cutting and red brass.

49
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50
Table 25. Comparison of two methods in the homogeneityanalysis of cast and extruded aluminum brass.

Arsenic (%)

Material

(cast)

Set a a As Average Asb Average

Standard

deviation

cill8 1

2

0.0061

.0066

0.0064

01119 1

2

0.0365

.0376

0.0370

C1120 1 0.0779 0.0754J;

.0875^

. 0904c

2 .0822

0.080

. 0876°

. 0888c .0892°

(Extruded)

1118 1 0.0067

2 .0067

1119

1120

0.0865 0.0124

0,.0067

1

2

. 0387

.0384

0,,0386

1 . 0847 o 08l5^

.0877^

.09iiu 0.862

2 .0850

0,.0848

0.0877^

.0877?

.o886 d

.03

O.O898 .002

Distillation and titration (sample weight l4_, 5 and 2.5 g

, respectively)

Spectrophotometric (sample weight 0.2, 0.3 and 0.4 g

respectively)

, Different position in rod.

Different extrusions.

(R. K. Bell)

51
Table 2b. Homogeneity and precision of analysis of

extruded and cast aluminum brass. Minor

constituent antimony.

Material

(cast)

Set Sb

Antimony {%)

Average

Standard

deviation

C1118 1

2

0.0118

.0105

0.0112 0.0009

C1119 1

2

0.0533

.0539

0.0536 0.0004

C1120 1

2

0.1091

.1034

0.1062 0.0040

(extruded)

E1118 1

2

0.0113

.0093

0.0103 0.0014

E1119 1

2

0.0523

.0484

0.0504 0.0028

E1120 1 0.0994

.1008

0.1001

(R. K.

0.0010

Bell)

Table 27. Homogeneity and precision of analysis of extruded free-cutting brass (major components).

Standard

reference Standard

material No. Element Position Average deviation

09 D12

1105 Cu(#) 63.725 63.726 63.725 0.006

P {%) 0.001 0.001 0.001 0.001

1105 CuK

P \%

Bulk

63.714

0.001

63.719

0.001

63.716

0.001

0.006

0.001

(R. K. Bell)

52
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53
3. Limestone, Dolomite and Clays

a. Lime s t one -homogene i ty . After the material was

screened through a 200-mesh sieve homogeneity tests were

performed on the fines, coarse and the sample fractions.

The tests included hydrochloric acid insoluble SiOp, total

Si Op (corrected for soluble SiOp) and loss on ignition.

The test results are summarized in Table 29.

Table 29. Homogeneity data for limestone.

Test Fines Coarse Sample

~~w ~w~ ~~w~

Insoluble 7.15, 7.29 5.43, 5.40 6.35, 6.29, 6.35

in HC1

Si0

2 5.37, 5.29 ^.29, 4.25 4.91, 4.91, 4.79

Loss on 40.54 41.10 40.90, 40.89,

ignition 40.86

b. Feldspar- stability . Most of the homogeneity

tests and analyses have been completed on Standard Reference

Materials la and 88a. Moisture tests and the determination

of C0p were conducted on feldspars, 70a and 99a, to

determine their stability during storage.. While this is not

strictly a homogeneity test, it provides an index of

stability of the material on prolonged storage. The samples

were dried at 110 °C and the carbon dioxide and hydrogen

were determined by combustion in a micro C and H apparatus

at 750 °C or by a Meeker Burner. To be certain that the

carbon dioxide and the hydrogen were evolved quantitatively,

various fluxes were used during combustion. The data are

summarized in Table 30*

54
Table 30. Direct determination of carbon dioxide

and water (hydrogen) in feldspar.

Sample Heating 70a 99a

Flux weight time "C"C~ HTO C0?

H

p

(g) (min) {%) {%) {%) {%)

wc^ 0.25 i5 a 0.035 o.4o8 0.106 0.230

^ .029 .448 .104 .269

.022 .410 .120 .231

W0^ .5 ^5

a .031 .414 .106 .237

V2 5

.15 10 .024 .378 .135 .243

No flux .25 10 .032 c 402 .135 .226

a o ,Carbon and hydrogen apparatus at 750 C.

Meeker burner.

c. Clay . Similar tests were performed on flint

clay, 97a and plastic clay 98a. In these tests, the drying

condition at two different temperatures was evaluated and is

summarized in Table 31 . Drying at II4O °C produced a constant

weight loss. These data are being checked by a thermogravimetric procedure.

Table 31. Drying conditions for flint clay, 97a and

plastic clay, 98a.

Test Conditions

Drying 132 hrs. at 110 °C;

additional 92 hrs.

at 140 °C

Total

Drying 66 hrs at 140 °C

Loss on 1.5 hr at 1000 °C

ignition

Loss in percent

97a 98a

0.86 1.77

.18 0.25

1.04 2.02

1.09 2.05

13.l8 a 12.11a

Dried basis.

ss
D. Cooperative Work with Outside Laboratories

Until now the Quantitative Separations Section through

direct contacts with outside industrial or scientific

laboratories had obtained their cooperation in checking

analytical results prior to the issuing of a certificate

for the standard reference material. Presently this function

is in the process of being transferred to the respective

coordinators in the Office of Standard Reference Materials.

Prom a list of several hundred laboratories, a score or less,

representative establishments, whose experience in the analysis

of these materials is well-established, were selected and

after the homogeneity tests were completed, samples of the

materials were sent to them. The results from these

cooperators were evaluated statistically and are also based

on the experience of the analyst and the accuracy that might

be expected from a given method. Those values falling within

the pre-established limits of errors of the methods are

incorporated in the certificate.

Whenever disagreement is encountered, consultation follows

to ascertain the cause of the bias. An example of this was the

case of the iron ore SRM (NBS 27e) in which the reported values

for iron and silica were outside the accepted error limits.

As shown in Figure 1% , the initially scattered and biased

values after they were rechecked fell in line with those

established at the Bureau. The error in the iron determination

was eliminated when the laboratories used the NBS dichromate

as the primary standard in place of a "pure" iron wire. In

the case of silica a double dehydration step yielded the

corrected values. In another example, the difficulty

encountered by the cooperating laboratories in obtaining

agreement for trace amounts of manganese was eliminated when

the cooperators used redistilled water instead of demineralized

water in their sample solution step. Traces of organic matter

from the resin bed caused the reduction of permanganate and

lead to low results. The current problem under study is the

determination of aluminum for which values obtained in this

section are 0.1 per cent lower than reported by the

cooperators

.

(J. R. Shultz and 0. Menis

)

56
LAB

A

B

C

D

E

F6

H

IJK

L

M

N

IRON (66.6)

(%)

66.48 .56 .64 .72 .80

I I I I I I I I I I I (NBS)

Si02(3.6)

(%)

3.40.48 .56 .64 .72

LAB

A (NBS)

B

C

D

E

F6

H

IJK

L

M

N

I I I I I I I I I I I

i i i i \ i I i I M I I I 1 I I I I I I I

A

B

C

D

EF

G

H

IJK

L

M

N

VALUES AFTER RECHECK

1 I I I

I

I I I I I I

I I 1I I FINAL VALUE 66.58

A

B

C

E

FG

H

IJK

L

M

N

VALUES AFTER RECHECK

1 I I I I I I I I n

ii i i FINAL VALUE 3.65

Figure 15

Correction of bias between cooperating

laboratories (results before and after

reevaluation for Pe and SiCu determinations)

57
7. URANIUM UMPIRE PROGRAM

A. Status of Current Program

Since 191; 9 NBS has performed the umpire analyses

required by the USAEC uranium procurement program. Improved

understanding and control of sampling and analysis problems

have brought about a marked decline from the peak of about

900 umpire requests in 1959* to 110 in 1965 and led to the

narrowing of acceptable limits of error in uranium assays to

less than 0.20 per cent. These circumstances plus the

approaching expiration of the existing AEC foreign contracts

designating NBS as the umpire, obviate the need for an

uranium umpire program at NBS. Consequently a close-out of

the program was initiated in 196I|_. Because the experience

at NBS on a variety of materials over a long period of time

has provided the accepted standard by which the uranium

industry has evaluated its performance, NBS continued to

provide umpire analyses, with a planned cut-off date of

July 1965> while also taking action to assure continued

availability of NBS uranium assay "know-how". Duplicate

determinations of uranium in each of the 110 umpire samples

received between July 1, 1961; and May 15, 1965 will be

completed in June. These include 9 foreign samples in

addition to those from 15 domestic producers. A comprehensive

and detailed account of the umpire program at NBS was written

as a guide for the use of future umpires and other groups

analyzing uranium, and is being prepared for publication in

the NBS 260 series. Also, twenty extra samples were assayed

for use by AEC in qualifying a new umpire.

B. Participation in the AEC-GAE Program

Participation in the AEC General Analytical Evaluation

Program (GAE) was continued.

The GAE program, designed to permit laboratories

performing analyses for the Commission to evaluate their

performance, and coordinated by. the Commission's

New Brunswick Laboratory, dealt with four types of uranium

concentrates each year from Aug. 1961 to Sept. 1961;. In the

current (fifth) year the program involves the analysis by

each of four laboratories (NBS, NBL, MCW and LPI) of

51; GAE samples representing 3 types of concentrates. Half of

the samples are AEC reference samples. Every three weeks each

cooperating laboratory receives three samples, in any

combination of materials and including both production and

disguised reference samples. These GAE samples are

independent of the umpire samples received by NBS.

58
All GAE results have been evaluated in NBL reports.

The general reproducibility is illustrated in Figure 16,

taken from an NBL report showing deviations from the

average for the Homestake-Sapin reference material between

Sept. 1963 and April 1965* Each point represents the assay

of one bottle of material. The inner, solid lines represent

95 per cent probability limits for the laboratory average and

the outer, dashed points represent 95 per cent probability

limits for a single plotted point. Bottling reliability has

greatly improved since the 1950' s, but the variability of

the Dawn reference material (Sept. 1963-Aug. I96I4.) indicated

that unsuspected sampling variations may still occur, and

emphasized the continued need for basing assay evaluations

on a standard of known composition, such as NBS No. 950 a » The effect of variations in composition on assay is still

determined by adding approximate amounts of appropriate

impurities to known amounts of the high purity standard

uranium.

(M. S. Richmond and J. R. Baldwin)

59
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60
8. URANIUM AND PLUTONIUM ISOTOPIC STANDARDS

A. Introduction

To meet the need of accurate isotopic uranium and

Plutonium standards for industry and science in the atomic

energy field, a program of preparing synthetic mixtures of

these isotopes was undertaken.

Sixteen uranium isotopic standards, supplied by Oak

Ridge National Laboratory, are being re-evaluated by

preparing known mixtures of isotopes for mass spectrometer

calibration. For the determination of U-235 and U-238,

solutions were prepared from the primary enriched U-235 and

either the primary-* or secondary-* standard of depleted U-238

to calibrate the mass spectrometric measurements for the

Mass Spectrometry Section. For the determination of U-23I4.

and U-236, the standards are spiked with high-purity

U-233 "to give favorable ratios for mass-spectrometric

measurements

B. Assay Process of Uranium Oxide Prior to Blending of

Isotopes

In order to blend the depleted U-238 and enriched U-235

and to spike the standards, it is necessary to know accurately

to better than one part in ten thousand the amount of uranium

in each isotopic component. The stoichiometry of U~Or> used

as the starting material depends on the method of preparation

and on ignition conditions. An ignition procedure was

developed for U~0o to give a reproducible oxide for weighing

prior to its analysis. These standards were then analyzed

for uranium by constant current coulometry in Section 310* 05*

The following ignition cycle for the oxides was

developed: one hour at 900 °c in air (to correlate with

previous work), overnight at 1050 °c in air, followed by 1 hr

in oxygen at 850 °C. The ignitions were conducted in a quartz

tube and the samples were protected from water and carbon

dioxide in the air by weighing them in small glass

desiccators

The following Table 32 shows the ignition loss of the

isotopic standards, the depleted U-238 samples, and the

"The primary and secondary designations differentiate between

a higher purity isotope available in smaller quantities and

a less pure secondary isotope standard.

61
Table 32. Reproducibility of the ignition loss of

LUOo samples.

Loss of weight for U^Og after an ignition cycle'

Number of

Sample runs Average loss

Standard

deviation

u-005 6 0.0394 O.OOlg

U-010 6 .0392 .OOlg

U-015 3 .0307 .0007

U-020 5 .0484 .ooi

2

U-030 3 .0507 .002

2

U-050 6 -.0058b

.002g

U-100 5 .0319 .002^^

u-150 3 .0287 .000g

U-200 3 .0280 .00^

U-350 3 .0377 .0034

U-500 5 .0971 .0034

U-750 3 .0373 ,001g

U-800 3 .0398 .0007

U-850 3 .0471 .0031

U-900 3 .0676 .0004

U-930 3 .0639 .ooo

9

Secondary

depleted

22 .0481 .003

Pr imary

depleted

8 .1037 .003g

Primary

enriched

20 .779 • 03

5

' o,

, Initial sample weight minus final weight at 850 C.

A modified procedure was used in the preparation of this

material by 0RNL.

62
enriched U-235 sample. The primary enriched sample contained

a relatively high percentage of water and appeared to be

absorbing additional moisture as the ignition loss of

individual samples increased with time. Based on the calculated values of standard deviation of replicate samples

taken through the ignition cycle, the largest error introduced

in the weight of a gram 'of the final' oxide was less than

i\. parts per hundred thousand. In most cases, it was smaller

by a factor of two. A thermogravimetric analyzer has recently

been acquired and its use will enable us to understand better

the stoichiometry of U~0n and to help check the accuracy of

the ignition procedure-^ see Gravimetry Section). It should

be feasible then, by means of a reduction and oxidation

cycle to determine both the stoichiometry and concentration

of the uranium in the sample, and thus, eliminate the need

for the coulometric titration.

In cooperation with Section 310.05 work is in progress

to determine the assay of uranium oxide prepared by

different procedures and ignited by the preceding procedure.

C . Preparation of Isotopic Mixtures

Mixtures of enriched U-235 and depleted U-238 samples

were prepared to enable a mass discrimination factor to be

determined on the mass spectrometer. Five mixtures were

prepared with a U-235 "to U-238 atom ratio of 8.95 to 9.05,

five mixtures with a ratio of 0.99 to 1.01 and five mixtures

with a ratio of O.110 to 0.112. The primary depleted U-238

was used in preparing the mixtures with a ratio of 0.99 to

1.01 and the secondary depleted U-238 was used to prepare

the others

Each sample was ignited, by the ignition procedure

developed to give reproducible oxides, using the calculated

weight of sample to give the desired ratio. The platinum

boat and U~0n sample were carefully transferred to a

250-ml teflon bottle. After both the depleted and enriched

samples had been ignited and transferred to the bottle,

sufficient HN0~ (1+1) was added to the bottle to give a

HN0„ (1+19) and 5 mg U per milliliter solution when

diluted with sufficient water. The bottle was sealed with

a teflon-lined cap and the sample dissolved by heating on a

steam bath. After cooling, enough water was added to give

a HN0- (1+19) solution.

Known amounts of U-233 were also added to the uranium

isotopic standards to determine their U-23^|- and U-236 content.

This was done by adding weighed amounts of U-233 solution to

solution of the samples. Two sets of samples were spiked

with two separate U-233 solutions of approximately O.lg

each. To one sample of. each kind, U-233 was added to make

63
it approximately 1% more than the estimated U-23lj- content

and to the other sample of each kind, U-233 was added to make

it approximately 1% less than the estimated U-23lj. content.

Additional samples were spiked at each change of U-233

dilution, to check whether any errors were made in the

dilution procedure.

Each sample was ignited by the ignition procedure

developed to give reproducible oxides. The platinum boat

and U-Oq sample were carefully transferred to teflon bottles.

The samples were dissolved in HNO_ (1+1) by heating on a steam bath. After dissolving, enough water was added to

make the solution approximately HNO_ (1+7). The U-233

sample was dissolved last and it was diluted to approximately

1 mg of U^On per gram of solution HNO (1+19) . The cap

on the U-233 bottle was replaced with a similar cap

containing a piece of polyethylene tubing shaped for use as

a squirt bottle. The U-233 was then added by squirting

U-233 solution into the sample bottles. By weighing the

U-233 bottle before and after the addition the amount

of U-233 added can be calculated. The sample solutions were

diluted with water to obtain a HNO_ (1+19) solution containing 5 nig U per ml. The "spiked" solutions were then

submitted for mass spectrographic analysis.

Based on this study a table of "best estimate" values

has been sent to all purchasers of uranium isotopic

standards

.

(L. A. Machlan)

D. Plutonium Isotopic Standard 9li8

1. Preparation of Plutonium Isotopic Standards

The plutonium isotopic standard was prepared by the

New Brunswick Laboratory of the Atomic Energy Commission in

the form of plutonium sulfate tetrahydrate from metal.

.The standard was bottled and samples for homogeneity testing

by the ^,10,0l\. personnel at New Brunswick. The samples were

packaged in 2R containers as required by ICC regulation and

after transfer to NBS the screw caps and joints were coated

with plastic "Seal-Stop". Preliminary measurements by mass

spectrometry indicated the material was isotopically

homogeneous, and the sample was distributed to a selected

group of cooperators

.

2

.

Separation of Americium

The plutonium standards which were to be certified

for Pu-239, Pu-2i|.0, Pu-2[|.l, and Pu-2]+2 isotopic composition

6k
required a separation of Am-2l\.l. The Fu-21^1 decays to

A111-2I4.I which interferes with the mass-spectrometry measurement for P'u-21|1. A procedure was adapted for the separation

of americium from plutonium by anion- exchange . The sample

was dissolved in 8N nitric acid and added to a small column

of Dowex 1 x 1| resin (1.3 cm high by J4..5 flim diameter).

The americium was removed by elution with 8N nitric acid

and the plutonium was then removed with O.3N nitric acid.

Section 310. 06 then carried out mass-spectrometry measurements on these solutions. Values obtained on duplicates of

three samples taken at the beginning, middle, and end of the

bottling are given in the following table.

Table 33. Atom per cent corrected to June 1, 1964.

Sample Pu-239 Pu-240 Pu-24l Pu-242

1 91.5693 7.9042 0.6937 0.0327

*2 91.3599 7.9H

9

.6950 .0331

3 91.3620 7.9100 .6949 .0330

\ 91.3661 7.9063 .6945 .0330

5 91.3625 7.9104

7.9074

.6940

0.6946

.033

Average: 91.3649 0.0330

Standard

deviation: 0.0041 0.0040 0.0007 0.0001

(M. S. Richmond and L. A. Machlan)

E. Miscellaneous

1. Bottling and Packaging Radioactive Samples

Because of the radioactivity of the material, all

bottling of uranium isotopic standards was done in the "hot

lab". Approximately 1300 samples have been bottled in the

past year. Approximately twelve thousand additional samples

are yet to be bottled.

Approximately 180 plutonium metal standard 949a were

packaged in 2R containers as required by ICC regulations and,

in addition, the screw caps and joints were coated with

plastic, "Seal-Stop".

Of the uranium oxide 950a for chemical assay, approximately 650 samples were bottled for sale.

65
2. Distribution of Uranium and Plutonium Standards

In order to ensure observance of health and safety

regulations applicable to the distribution of source and

fissionable materials, an experienced chemist was directly

responsible for each shipment until March 1965* By then

packing details had been standardized as shown in the

attached drawings, Figure 17a and 17b, and also the

procedures for processing orders were written; subsequently,

responsibility for strictly clerical aspects of handling orders

of these materials were assumed by the Office of Standard

Reference Materials. However, personnel of this section

continue to be the vault custodians, supplying standard reference materials and maintaining inventory records; and to

serve as the consultants providing the shipper with radioactive shipment details that aim to insure (and coordinate)

compliance with NBS, AEC, ICC, carrier and receiver

regulations

.

3

.

Clean-Up Program

The changing program of the section has resulted in

considerable moving or disposal of materials and equipment.

This included the entire contents of one large laboratory

(Rm. 306) and most of one small laboratory (Rm. 316). The

iso topic uranium group made 3 shipments effecting the

transfer of 800 kg of Congo ore, 28 kg of high-grade pitchblende, and nearly 11 kg of three highly enriched materials,

from NBS to AEC storage sites. Surplus and waste U-233

oxide from three lots including two lots last used in 1959

were accounted for and disposed of.

(M. S. Richmond)

66
PACKING DETAILS FOR NBS NO. 948 (ISOTOPIC STANDARD)

Material : PLUTONIUM sulfate tetrahydrate

Emitted Radiation ; Alpha

Specific Activity : 76 mCi/g

Unit Net Weight : 0.25g (Pu)

Unit Legal Weight : 21 oz (includes sealed pipe)

Commodity Code Number : 5150020

Outside Shipping Container : ICC Specification 12B fiberboard box

Size 10" x 10" x 5" for: 1 unit, to 6 units,

Estimated Gross Weight: 5 lb, to 12 lb, or 12" x 12" x 12" for: 7 units (15 lb) to 16 units (30 lb gross)

Labeled for : Radioactive Material, Class D poison, Group III

LABELED GLASS BOTTLE

WITH TEFLON -LINE0 SCREW CAP (l-in.0.0. X

|i/,-in. OVERALL HEIGHT)

CARDBOARD CASE (

I '/« in O.D. X 2

3/8

-in. LENGTH, PACKED IN PLASTIC FILM AND SPONGE

SEALED PLASTIC TUBE, 0.006 -in. WALL THICKNESS

(FILLS CASE)

SCREW CAPS AND

JOINTS COATED WITH

Pl.ASTIC,"SEAL-STOP"

CAPPED PIPE,4-m. OVERALL LENGTH ( CUSHIONED IN SHREDDED PAPER)

SCHEDULE 40 STEEL PIPE

(1.66-in. O.D. X 0.14-in WALL)

FIBERBOARD BOX (10- in. X 10-in. X 5- in.

PU(S04 ) 2 .4H 2

Figure 17a. Packing details for plutonium NBS

Standard Reference Materials.

67
PACKING DETAILS FOR NBS NOS. U-010 THROUGH U-930

Material : U-235-ENRICHED U„O

ft , with U-235 abundance of

17» (in U-010) to 93% (in U-930)

Emitted Radiation : Alpha

Specific Activity : up to 0.07 mCi/g (depending on enrichment)

Unit Net Weight : l.Og (U)

Unit Legal Weight : 1 oz (includes cardboard case)

Commodity Code Number : 5150020

Container : The material is packed as shown below and, except for

domestic shipments of less than 1.35 mCi, the material

is further packed in an ICC Spec. 12B fiberboard box

(10" x 10" x 5", for up to 32 units, with an estimated

gross weight of 4 to 6 lb).

Labeled for : Radioactive Material (according to activity range)

CARDBOARD CASE

( l'/4 -in.0.D.X 2%-in. LENGTH

)

LABELED GLASS BOTTLE, WITH HARD PLASTIC SCREW CAP (l-in.0.0. Xl'/2 -in. OVERALL

HEIGHT, WRAPPED IN PAPER)

U-235 -ENRICHED U s 8 FIBERBOARD.TRIPLE - SLIDE, 8-UNlTB0X(6 ,/4-'n-X3 l/2 -in.X3-in.)

Figure 17b. Packing details for uranium NBS

Standard Reference Materials.

68
9. PERSONNEL AND ACITVITIES

A. Personnel List

Quantitative Separations Section, Oscar Menis, Section Chief

Mrs. M. Pantazis, Secretary

J.. R. Baldwin

R. K. Bell

B. B. Bendigo

R. W. Burke

E. R. Deardorff

L. A. Machlan

F. J. Palumbo

M. S. Richmond

K. M. Sappenfield

J. I. Shultz

J. T. Sterling

Talks

R. W. Burke, A.C.S. Meeting in Miniature at U. of

Maryland, May "J, 1965 > "Application of Spectrophotometry to Trace Element Analysis at the Submicrogram

Level - Determination of Nanogram Quantities of

Beryllium"

C. Committee Activities and Education

E. R. Deardorff

Attended Thermoanalysis Institute, Pairleigh

Dickinson University.

69
L. A. Machlan

Member, Board of U. S. Civil Service Examiners.

Completed course, "Electronics for Scientists",

3 weeks at U. of Illinois.

0. Menis

Co-chairman of the Chemistry Program for the Pittsburgh

Conference on Analytical Chemistry and Applied

Spectroscopy, March 1965>.

Chairman of Symposium of "Burnup Analysis" at the

ANS Meeting, Gatlinburg, Term. , 1965.

M. S. Richmond

Completed course, "Radiochemistry", N.B.S. Graduate

School

.

J. I. Shultz

ASTM Activities

Chairman of Lundell-Bright Memorial Award Committee.

Member of Advisory Committee of Committee E3

(Chemical Analysis of Metals).

Vice-Chairman of Division F (Ferrous Materials)

of Committee E3.

Chairman of Task Force for revising and rewriting

ASTM methods of analysis for ferrous materials.

Member of Divisions M and G of Committee E3«

NBS

Chairman of the Suggestion Program Subcommittee on

Technical Procedures.

D. Publications

Shultz, J. I., Standard Reference Materials: Methods

for the Chemical Analysis of White Cast Iron

Standards, NBS Misc. Publ. 260-6, July 1965-

Bell, R. K., Standard Reference Materials: Methods for

the Chemical Analysis of NBS Copper-Base Spectrochemical Standards, NBS Misc. Publ. 260-7, In Press.

Richmond, M. S., Standard Reference Materials: Analysis

of Uranium Concentrates at the National Bureau of

Standards, NBS Misc. Publ. 260-8, In Press.

70
10. ACKNOWLEDGEMENTS

The Quantitative Separations Section acknowledges the

help of Rolf A. Paulson who was the acting chief in the

first half of the period covered by this report. The

section also wishes to thank Mr. John Hague for his

guidance and discussions of the various aspects of standard

reference materials, especially of the isotope standards

program.

The section acknowledges Mrs. R. S. Maddock's assistance

in preparing this report. Special appreciation is expressed

to M. Pantazis as the section's secretary for her tireless

efforts in getting this report typed.

71
11. REFERENCES

[I] Schmidt j R. W. and Reilley, C. N., Anal. Chem. 29,

264.(1957). ~~

[2] Knowles, H. B. and Redmond,, J. C, J. Am. Ceramic

Soc. 18, 106 (1955).

[5] Bendigo, B. B. and Bell, R. K. , J. Res. NBS 64A5,

255 (I960).

[4] Ibid.

[5] Spicer, G. S. and Strickland, J. D. H. , Anal. Chim.

Acta 18, 231 (1958).

[6] Freegarde, M. and Cartwright, J., Analyst 87, 2l4 (1962).

[7] Hayes, M. R. and Metcalfe J., Analyst 87, 956 (1962).

[8] Adam, J. A., Booth, E. and Strickland, J. D. H., Anal.

Chim. Acta 6, 462 (1952).

[9] Ringbaum, A. and Ostenholm, K. , Anal. Chem. 25, 1798

(1953).

[10] Kortum, G. , Angew. Chem. 50, 193 (1957).

[II] Bastian, R. , Anal. Chem. 21, 972 (1949).

[12] Hiskey, C. F. , Ibid. 21, 1440 (1949).

[15] Hiskey, C. F., Rabinowitz, J. and Young, J. G. , Ibid.

22, 1464 (1950).

[14] Hiskey, C. F. and Firestone, D. , Ibid. 24, 542 (1952).

[15] Reilley, C. N. and Crawford, CM., Ibid. _27, 716 (1955).

[16] Menis, 0., ORNL Master Analytical Manual, TID 7015,

Methods No. 1, 215410 and 900715410.

[17] Gordon, C. L. , Schlecht. W. G. and Wichers, E.,

J. Res. NBS 55, 457 (1944).

[18] ASTM Methods of Chemical Analysis of Metals, p. 513

(I960).

[19] Karp, H. S., Lewis, L. L. and Melnick, L. M. , J. Iron

Steel Inst. 200, 10^2 (1962).

72
[20] Bennett , H., Spec. Ceram. Proc . Symp. Brit. Ceram.

Res. Assoc. , Stoke-on- T rent, 1959 , 339 (i960).

[21] Michaelis, R. E., Wyman, L. I., and Flitsch, R.

Standard Reference Materials: Preparation of NBS

Copper-Base Spectrochemical Standards, NBS Misc. Publ,

260-2, Oct. 1964.

73


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