This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles

for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Designation: D4075 − 06 (Reapproved 2017)

Standard Test Methods for

Rubber Compounding Materials—Flame Atomic Absorption
Analysis—Determination of Metals1
This standard is issued under the fixed designation D4075; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.

1. Scope 2.2 Other Documents:

1.1 These test methods cover the determination of metals in 2.2.1 Literature pertinent to the particular atomic absorption
rubber compounding materials by flame atomic absorption. spectrophotometric equipment used for the analysis espe-
cially the manufacturer’s recommendations for optimum
1.2 The test methods include the following materials: performance. Standard texts on atomic absorption by
Sections flame technique are also helpful.
Zinc oxide 11 – 20
1.3 The values stated in SI units are to be regarded as 3. Summary of Test Methods
standard. No other units of measurement are included in this
standard. 3.1 The compounding material is suitably sampled, pre-
pared according to the appropriate sections of these test
1.4 This standard does not purport to address all of the methods, and examined by flame absorption spectrophotom-
safety concerns, if any, associated with its use. It is the etry for metals.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.2 Sample preparation, procedures, calculations, and pre-
bility of regulatory limitations prior to use. (For a specific cision statements will be found in each section dealing with a
warning statement, see 6.1.) particular compounding material.
1.5 This international standard was developed in accor- 3.3 The analysis of metals in compounding materials de-
dance with internationally recognized principles on standard- pends on the skill of the operator in the use of the flame atomic
ization established in the Decision on Principles for the absorption equipment. It is, therefore, assumed that the opera-
Development of International Standards, Guides and Recom- tor is familiar with all aspects of this analytical technique. No
mendations issued by the World Trade Organization Technical details are given here for the proper operation of the equipment
Barriers to Trade (TBT) Committee. or interpretation of results obtained.
3.4 These test methods do not cover the determination of
2. Referenced Documents
metals in raw rubbers or finished products. See Test Methods
2.1 ASTM Standards:2 D4004 for these methods.
D4004 Test Methods for Rubber—Determination of Metal
Content by Flame Atomic Absorption (AAS) Analysis 4. Significance and Use
D4483 Practice for Evaluating Precision for Test Method
Standards in the Rubber and Carbon Black Manufacturing 4.1 These test methods are suitable for process control, for
Industries product acceptance, and for research and development.
E300 Practice for Sampling Industrial Chemicals
5. Apparatus
5.1 Balances, capable of weighing accurately to 60.1 mg or
1
These test methods are under the jurisdiction of ASTM Committee D11 on 60.1 g, depending on sample mass required.
Rubber and Rubber-like Materials and are the direct responsibility of Subcommittee
D11.11 on Chemical Analysis. 5.2 Hot Plate.
Current edition approved May 1, 2017. Published May 2017. Originally 5.3 Common Borosilicate Glassware, especially 10, 100,
approved in 1981. Last previous edition approved in 2012 as D4075 – 06 (2012).
DOI: 10.1520/D4075-06R17. 200 and 500-cm3 volumetric flasks.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.4 Pipets, of 1, 2, 5, and 10-cm3 capacity. One cubic
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on centimetre pipets graduated in tenths and hundredths are
the ASTM website. especially useful.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States

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 D4075 − 06 (2017)
5.5 Microlitre Syringes, 1 and 10 mm3 (µL) are recom- ZINC OXIDE
mended.
11. Scope
5.6 Plastic Bottles, suitable for storage of standard solu-
tions. 11.1 This test method covers the analysis of zinc oxide for
copper, cadmium, lead, and manganese.
5.7 Atomic Absorption Spectrophotometer, operating in the
flame mode. The instrument must be operated according to the 11.2 Any zinc oxide, suitable for rubber compounding, may
manufacturer’s directions for optimum performance for flame be analyzed by this procedure.
operation. 11.3 This test method is not suitable for zinc oxide with lead
content above about 1.0 % because of dissolution problems.
6. Reagents
11.4 This international standard was developed in accor-
6.1 Standard solution for metals to be determined in each dance with internationally recognized principles on standard-
compounding material may be prepared from pure metals, ization established in the Decision on Principles for the
metallic compounds, or purchased from a chemical supply Development of International Standards, Guides and Recom-
house as standard solutions. The usual concentrations of mendations issued by the World Trade Organization Technical
solutions is 1000 µg of the metal per cubic centimetre of Barriers to Trade (TBT) Committee.
solution. Suitable dilutions with water will bring these concen-
trated solutions into the linear working range of the instrument. 12. Summary of Test Method
It is recommended that standards below 1µ g/cm3 be prepared 12.1 A “slurry” of zinc oxide and water is heated with HCl,
fresh, while those above 1µ g/cm3 may be stored. (Warning— to which a small amount of HNO3 is added. The metal sought
Observe all recognized health and safety precautions while is determined by flame atomic absorption.
carrying out this procedure. All reagents shall be of analytical
grade, and distilled, deionized, or distilled deionized water 13. Significance and Use
shall be used for sample preparation and required dilutions.) 13.1 The principal reason for analysis of zinc oxide for
copper, cadmium, manganese and lead is for quality assurance,
7. Sampling
but this test method may be used for other purposes, such as
7.1 Sampling shall be carried out in the best possible way to research, process control, etc.
ensure that the sample is representative of the lot (see Practice
E300). 14. Apparatus
7.2 The analyst shall select a test portion from the sample in 14.1 See Section 5.
such a way that it is as representative of the sample as possible.
This sampling shall be at the discretion of the analyst. 15. Reagents
15.1 See Section 6, and in addition:
8. Calculation
15.2 Hydrochloric Acid (HCl), concentrated,
8.1 Calculation may be by graph, by equation, or by
15.3 Nitric Acid (HNO3), concentrated.
calibration techniques appropriate to the atomic absorption
spectrophotometer being used. 16. Sampling
8.2 Instrument calibration methods (possible with more 16.1 See Section 7.
modern equipment) shall be carried out as suggested by the
manufacturer. 17. Procedure
17.1 Accurately weigh a 0.2 to 10.0-g sample. Weigh to
9. Report
0.1 mg for small samples and 2 6 0.1 g for large samples into
9.1 Report the metal content as a percent, if more than or a 150-cm3 beaker. Add enough water to make a thick “slurry.”
equal to 0.1 % or as milligrams per kilogram, if less than Add enough concentrated HCl to effect complete dissolution of
0.1 %. the test portion. For small test portions, 10 cm3 will suffice, for
NOTE 1—Micrograms per gram, parts per million, and milligrams per larger test portions, up to 30 cm3 may be needed.
kilogram are equivalent. Micrograms per gram and milligrams per NOTE 2—Failure to observe this sequence will result in a hard cake of
kilogram are preferred in SI. zinc oxide, which will be difficult to dissolve in the water–acid mixture.

10. Precision and Bias 17.2 Heat the solution on a hot plate to the boiling point,
then add 1 to 2 cm3 of concentrated HNO3. Continue heating
10.1 The precision statements found under each individual for no more than 5 min. Remove the beaker from the hot plate,
compounding material were prepared in accordance with allow it to cool and quantitatively transfer the solution to a
Practice D4483. Refer to this practice for terminology and 200-cm3 volumetric flask making it up to volume with water.
other testing statistical concept explanations.
NOTE 3—Variations in the amount of test portion to weigh and final
10.2 A test result is the average of two individual determi- volume of solution is left to the discretion of the analyst and must be
nations that fall within the LSD (Least Significant Difference) determined by prior knowledge of the approximate amount of copper,
limit for repeatability as stated in each precision section. cadmium, and lead in the type of zinc oxide being analyzed.

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 D4075 − 06 (2017)
17.3 Carry a blank throughout the entire procedure, using TABLE 1 Details on Interlaboratory Precision Test Programs
the same quantities of reagents but without a test portion. Number of Types of
(Tested)
Subtract any positive blank value, in an appropriate manner, Analysis Number
Laboratories ZnO
of Days
before calculating the metal content of the zinc oxide.
Copper in ZnO 8 1 3
17.4 Complete the analysis, using standard flame atomic Cadmium in ZnO 8 2 3
absorption techniques appropriate to the instrument used and Manganese in ZnO 8 1 3
following the manufacturer’s directions for optimum instru- Lead in ZnO 8 2 3
ment performance.
NOTE 4—Zinc oxide solution for measurement must fall within the with this test method). The appropriate value is that value of r
linear range of the instrument. Any solution that does not meet this or R associated with a mean level in Table 2 closest to the mean
criterion must be diluted suitably to fall within this range.
level under consideration at any given time, for any given
18. Calculation material in routine testing operations.
18.1 See Section 8. 20.6 Repeatability—The repeatability, r, of this test method
has been established as the appropriate value tabulated in Table
19. Report 2. Two single test results, obtained under normal test method
19.1 See Section 9. procedures, that differ by more than this tabulated r (for any
given level) must be considered as derived from different or
20. Precision and Bias3 nonidentical sample populations.
20.1 This precision and bias section has been prepared in 20.7 Reproducibility—The reproducibility, R, of this test
accordance with Practice D4483. Refer to Practice D4483 for method has been established as the appropriate value for any
terminology and other statistical calculation details. parameter tabulated in Table 2. Two single test results obtained
20.2 A Type 1 (interlaboratory) precision was evaluated. in two different laboratories, under normal test method
Both repeatability and reproducibility are short term, a period procedures, that differ by more than the tabulated R (for any
of a few days separates replicate test results. A test result is the given level) must be considered to have come from different or
average value, as specified by this test method, obtained on two nonidentical sample populations.
determinations or measurements of the property or parameter 20.8 Repeatability and reproducibility expressed as a per-
in question. centage of the mean level, (r) and (R), have equivalent
20.3 Table 1 gives the details on the interlaboratory testing; application statements as above for r and R. For the (r) and (R)
materials (types of zinc oxide), number of laboratories, number statements, the difference in the two single test results is
of testing days. expressed as a percentage of the arithmetic mean of the two test
results.
20.4 The results of the precision calculations for repeatabil-
ity and reproducibility are given in Table 2. 20.9 Bias—In test method terminology, bias is the difference
between an average test value and the reference (or true) test
20.5 The precision of this test method for any analysis may property value. Reference values do not exist for this test
be expressed in the format of the following statements which method since the value (of the test property) is exclusively
use what is called an “appropriate value” of r, R, (r), or (R), that defined by the test method. Bias, therefore, cannot be deter-
is, that value to be used in decisions about test results (obtained mined.

3
21. Keywords
Supporting data have been filed at ASTM International Headquarters and may
be obtained by requesting Research Report RR:D11-1019. 21.1 atomic absorption analysis; metals; zinc oxide

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 D4075 − 06 (2017)
TABLE 2 Type 1—Precision for Copper, Cadmium, Manganese, and Lead in Zinc Oxide
NOTE 1—
Sr = within laboratory standard deviation.
r = repeatability (in measurement units).
(r) = repeatability (in percent).
SR = between laboratory standard deviation.
R = reproducibility (in measurement units).
(R) = reproducibility (in percent).
(ZnO) (mg/kg) Within Laboratories Between Laboratories
Material Analysis For Mean Value Sr r (r) SR R (R)

1 copper 6.5 0.456 1.29 19.9 0.930 2.63 40.5

1 cadmium 1.9 1.07 3.03 159.0 1.41 3.99 210.0
2 cadmium 236.0 5.32 15.1 6.40 27.4 77.5 32.9
1 manganese 41.0 1.19 3.37 8.22 5.38 15.2 37.1
1 lead 12.0 0.70 1.98 16.5 1.81 5.12 42.7
2 lead 932.0 9.42 26.7 2.86 63.0 178.0 19.1

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