ASTM D126-87(2012)
(Test Method)Standard Test Methods for Analysis of Yellow, Orange, and Green Pigments Containing Lead Chromate and Chromium Oxide Green
Standard Test Methods for Analysis of Yellow, Orange, and Green Pigments Containing Lead Chromate and Chromium Oxide Green
SIGNIFICANCE AND USE
4.1 These test methods are for analysis designed as an aid in quality of yellow, orange, and green pigments containing lead chromate and chromium oxide green. Some sections may be applicable to analysis of these pigments when extracted from whole paints.
SCOPE
1.1 These test methods cover procedures for the chemical analysis of yellow, orange, and green pigments containing lead chromate and chromium oxide green.
1.2 The analytical procedures appear in the following order:
Sections
Chrome Yellow, Chrome Orange, and Molybdate Orange
Organic Colors and Lakes
7
Moisture and Other Volatile Matter
8
Matter Soluble in Water
9
Lead Chromate
10 and 11
Total Lead
12
Sulfate
13 and 14
Carbon Dioxide
15
Molybdenum
16 and 17
Extenders
18-22
Calculation of Substances Other than Insoluble Lead
Compounds
23 and 24
Pure Chrome Green and Reduced Chrome Green
Organic Colors and Lakes
25
Moisture and Other Volatile Matter
26
Matter Soluble in Water
27
Iron Blue
28
Lead Chromate
29 and 30
Barium Sulfate and Insoluble Siliceous Material
31
Total Lead
32
Sulfate
33
Calcium Oxide Soluble in Acid
34 and 35
Extenders
36
Calculation of Insoluble Lead Compounds
37
Chromium Oxide Green
Organic Colors and Lakes
38
Moisture and Other Volatile Matter
39
Matter Soluble in Water
40
Total Chromium as Chromium Oxide
41
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Note 3.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D126 − 87 (Reapproved 2012)
Standard Test Methods for
Analysis of Yellow, Orange, and Green Pigments Containing
Lead Chromate and Chromium Oxide Green
This standard is issued under the fixed designation D126; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber 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 responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 These test methods cover procedures for the chemical
bility of regulatory limitations prior to use. Specific hazard
analysisofyellow,orange,andgreenpigmentscontaininglead
statements are given in Note 3.
chromate and chromium oxide green.
1.2 Theanalyticalproceduresappearinthefollowingorder: 2. Referenced Documents
Sections
2.1 ASTM Standards:
CHROME YELLOW,CHROME ORANGE, AND MOLYBDATE ORANGE
D280Test Methods for Hygroscopic Moisture (and Other
Organic Colors and Lakes 7
Moisture and Other Volatile Matter 8 Matter Volatile Under the Test Conditions) in Pigments
Matter Soluble in Water 9
D521Test Methods for Chemical Analysis of Zinc Dust
Lead Chromate 10 and 11
(Metallic Zinc Powder)
Total Lead 12
Sulfate 13 and 14 D1013Test Method for Determining Total Nitrogen in
Carbon Dioxide 15
Resins and Plastics (Withdrawn 2007)
Molybdenum 16 and 17
D1193Specification for Reagent Water
Extenders 18–22
Calculation of Substances Other than Insoluble Lead
E11Specification forWovenWireTest Sieve Cloth andTest
Compounds 23 and 24
Sieves
PURE CHROME GREEN AND REDUCED CHROME GREEN
Organic Colors and Lakes 25
3. Summary of Test Methods
Moisture and Other Volatile Matter 26
Matter Soluble in Water 27
3.1 Chrome Yellow, Chrome Orange, and Molybdate Or-
Iron Blue 28
ange:
Lead Chromate 29 and 30
Barium Sulfate and Insoluble Siliceous Material 31
3.1.1 Organic colors and lakes are determined qualitatively
Total Lead 32
by boiling the sample in water, then ethyl alcohol, and finally
Sulfate 33
chloroform.
Calcium Oxide Soluble inAcid 34 and 35
Extenders 36
3.1.2 Moisture and other volatile matter are determined in
Calculation of Insoluble Lead Compounds
accordance with Test Method A of Test Methods D280.
3.1.3 Matter soluble in water is determined by boiling in
CHROMIUM OXIDE GREEN
Organic Colors and Lakes 38
water and filtering.
Moisture and Other Volatile Matter 39
3.1.4 Leadchromateisdeterminedbydissolvingthesample
Matter Soluble in Water 40
in dilute HCl, filtering and titrating potentiometrically with
Total Chromium as Chromium Oxide 41
FeSO solution after addition of HClO .
4 4
1.3 The values stated in SI units are to be regarded as
3.1.5 Total lead is determined by precipitation as lead
standard. No other units of measurement are included in this
sulfide solution with H SO and final precipitation as lead
2 4
standard.
sulfate.
1.4 This standard does not purport to address all of the
3.1.6 Sulfate is determined by dissolving the sample in
safety problems, if any, associated with its use. It is the
acetic acid, neutralizing with sodium carbonate, plus addition
1 2
These test methods are under the jurisdiction of ASTM Committee D01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Paint and Related Coatings, Materials, and Applications and are the direct contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
responsibility of Subcommittee D01.31 on Pigment Specifications. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2012. Published August 2012. Originally the ASTM website.
approved in 1922. Last previous edition approved in 2006 as D126–87(2006). The last approved version of this historical standard is referenced on
DOI: 10.1520/D0126-87R12. www.astm.org.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
D126 − 87 (2012)
of HCl to an aliquot followed by addition of BaCl to Committee onAnalytical Reagents of theAmerican Chemical
precipitate as barium sulfate. Society, where such specifications are available. Other grades
3.1.7 Carbon dioxide is determined by evolution. may be used, provided it is first ascertained that the reagent is
3.1.8 Molybdenum is determined by precipitation as the of sufficiently high purity to permit its use without lessening
sulfide, solution in HNO and H SO , addition of NH OH and the accuracy of the determination.
3 2 4 4
H SO . The solution is reduced in a Jones reductor, collected
2 4
5.2 Water—Unless otherwise indicated, references to water
under Fe (SO ) solution and titrated with KMnO solution.
2 4 3 4
for use in the preparation of reagents and in analytical
3.1.9 Extenders are either:
procedures shall be understood to mean reagent water con-
3.1.9.1 Calciumcarbonate,calciumsulfate,magnesiumcar-
forming to Type II of Specification D1193.
bonate or;
(a)The compounds in 3.1.9.1 are determined qualitatively
6. Preparation of Sample
by precipitation with ammonium solution.
(b)If chromium is present, it is reduced and the lead salts 6.1 Mix the sample thoroughly and take a representative
dissolved in dissolving solution. Hydroxides and hydrous portion for analysis. Reduce any lumps or coarse particles to a
oxides are precipitated by addition of HCl and NH OH and fine powder by grinding. Grind extracted pigments to pass a
filtered. CaC O is precipitated with calcium oxalate solution
No. 80 (180-µm) sieve (Note 1). Discard any skins that do not
2 4
and filtered, ashed and weighed as CaO. Alternatively, the pass through the sieve. Thoroughly mix the finely ground
precipitate is dissolved in H SO and titrated with KMnO .
pigment and preserve in stoppered and suitably identified
2 4 4
Magnesium is determined on the filtrate from calcium deter- bottles or containers.
mination by precipitation as the phosphate with ammonium
NOTE1—DetailedrequirementsforthissievearegiveninSpecification
phosphate solution.
E11.
3.2 Chromium Oxide Green:
6.2 Moisten the weighed portions of extracted pigments
3.2.1 Organic colors and lakes are determined qualitatively
with a small amount of suitable wetting agent (Note 1) before
by boiling the sample in water, then ethyl alcohol, and finally
adding reagents for analysis.
choloroform.
3.2.2 Moisture and other volatile matter are determined in
NOTE 2—A0.1% solution of sodium dioctylsuccinosulfonate has been
found satisfactory. (This material is sold under the trade name ofAerosol
accordance with Test Method A of Test Methods D280.
OT.)Wettingagentscontainingmineralsalts,sulfates,orsulfonateswhich
3.2.3 Matter soluble in water is determined by boiling in
may be hydrolyzed to sulfates, should be avoided; the use of alcohol is
water and filtering.
also undesirable because of its tendency to reduce chromates.
3.2.4 Total chromium as chromium oxide is determined by
NOTE 3—Warning: As the National Institute for Occupational Safety
dissolving the sample in dilute HCl, filtering and titrating
andHealthhasstatedthathexavalentchromiumcompoundsarehazardous
potentiometrically with FeSO solution after addition of to health, care should be exercised in preparation of the sample. The
wearing of a respirator and rubber or synthetic gloves are recommended.
HClO .
If hexavalent chromium materials come in contact with the skin, wash
thoroughly with soap and water.
4. Significance and Use
4.1 Thesetestmethodsareforanalysisdesignedasanaidin
quality of yellow, orange, and green pigments containing lead
chromate and chromium oxide green. Some sections may be
applicable to analysis of these pigments when extracted from
Reagent Chemicals, American Chemical Society, Specifications, American
whole paints.
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
5. Purity of Reagents and Water listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH, Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
5.1 Reagents—Unless otherwise indicated, it is intended
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
that all reagents shall conform to the specifications of the MD.
CHROME YELLOW, CHROME ORANGE, AND MOLYBDATE ORANGE
(Primrose, Lemon, and Medium Yellows; Chrome Oranges; Lead Molybdate or Basic Lead Chromate; Molybdate Orange)
ORGANIC COLORS AND LAKES colors resistant to the above reagents is unlikely, but may be
tested for by reference to procedures given in standard refer-
7. Procedure ence works.
7.1 Boil 2 g of the sample 2 min with 25 mL of water, let
settle, and decant the supernatant liquid. Similarly, boil the
residue with 25 mL of ethyl alcohol (absolute or 95%) and
decant as before. Likewise boil with 25 mLof chloroform and
again decant. If any one of the above solutions is colored,
organic colors are present. If all solutions remain colorless,
Reference may be made to the following: Payne, H. F., “Organic Coatings
organic colors are presumably absent.The presence of organic Technology,” Vol II, John Wiley & Sons, Inc., New York, NY, 1961.
D126 − 87 (2012)
MOISTURE AND OTHER VOLATILE MATTER 11.2 Alternatively, the solution may be reduced by a known
excess of FeSO solution and back-titrated with KMnO
4 4
8. Procedure solutioninthepresenceofMnSO ,orexcessKImaybeadded
and the liberated iodine titrated with Na S O solution, using
2 2 3
8.1 Determine moisture and other volatile matter in accor-
starch indicator.The iodine liberation method is not applicable
dance with Test Method A of Test Methods D280.
in the presence of molybdenum.
MATTER SOLUBLE IN WATER
TOTAL LEAD
9. Procedure
12. Procedure
9.1 Place 2.5 g of the sample in a graduated 250-mL flask.
12.1 Dissolve 0.5 g of sample as described in Section 11.
Add100mLofwaterandboilfor5min.Cool,dilutetoexactly
Add5mLofethylalcohol(95%orabsolute)andboiluntilthe
250 mL, mix, and allow to settle. Filter the supernatant liquid
chromium is reduced, as indicated by a green color. Filter if
throughadrypaperanddiscardthefirst20mL.Evaporate100
any insoluble residue is present, retaining the filtrate and
mLof the clear filtrate to dryness in a weighed dish, heat for 1
washings for the determination. Add NH OH (sp gr 0.90) to
h at 105 to 110°C, cool, and weigh. 4
this solution until a faint precipitate begins to form; then add 5
9.2 Calculation—Calculatethe%ofmattersolubleinwater
mL of HCl (sp gr 1.19) slowly, dilute to 500 mL, and pass a
as follows:
rapid current of H S into the solution until precipitation is
Mattersolubleinwater,% 5 R 32.5 3100 /S (1)
~ ! complete. Settle, filter, and wash with water containing H S.
where: 12.2 Rinse the precipitate from the filter (Note 5) into a
beaker containing 25 mLof HNO (1+3) and boil until all PbS
R = weight of residue, and
has dissolved. Add 10 mL of H SO (1+1) and evaporate to
S = specimen weight, g.
2 4
strong fumes of SO . Cool and add 50 mLof water and 50 mL
LEAD CHROMATE
of ethyl alcohol (95%) (Note 6). Let stand 1 h; then filter on
a tarred Gooch crucible. Wash with ethyl alcohol (95%), dry,
10. Reagents
ignite at 500 to 600°C, and weigh as PbSO .
10.1 Dissolving Solution—Saturate 1 Lof water with NaCl.
NOTE 5—If a trace of sulfide remains on the paper, the stained portion
Filter.Addtothefilteredsolution150mLofwaterand100mL
of the paper may be separately treated with bromine water, the paper
filtered off, and the filtrate added to the body of the solution.
of HCl (sp gr 1.19).
NOTE6—Anysulfurremainingfromdecompositionofthesulfidesmay
10.2 Ferrous Sulfate, Standard Solution (0.3 N)—Dissolve
be mechanically removed as a globule of solidified sulfur at this point.
86 g of FeSO ·7H O in 500 mL of water to which 30 mL of
4 2
SULFATE
H SO (sp gr 1.84) has been added with constant stirring.
2 4
Dilute to 1 L and standardize not more than 6 h before use by
13. Reagents
potentiometric titration against 0.7-g portions of K Cr O .
2 2 7
13.1 Barium Chloride Solution—Dissolve 117 g of BaCl ·
11. Procedure
2H O in water and dilute to 1 L.
11.1 Dissolve1gofthesamplein150mLofthedissolving
13.2 Dissolving Solution—See 10.1.
solution. Agitate for 10 to 15 min, keeping the solution cold
13.3 Sodium Carbonate Solution (saturated)—Prepare a
until dissolution is complete (Note 4). If dissolution is not
solution containing excess Na CO at laboratory temperature,
2 3
complete, filter through fine grade filter paper and wash with
and free of SO . Decant the clear solution for use as required.
three10-mLportionsofcolddissolvingsolution.Add10mLof
HClO (70%), dilute to 250 mL, and titrate potentiometrically
14. Procedure
with FeSO solution.
14.1 Digest 1.25 g of the sample with 100 mLof dissolving
NOTE4—Incompletesolutionofthepigmentisevidenceofthepossible
solution at 100°C for 5 min.Add 25 mL of glacial acetic acid
presence of barium sulfate, silica, silicates, or other acid-insoluble
extenders (see Section 18). Some chrome yellows may contain organic and 15 mL of ethyl alcohol and heat gently for 10 min to
addition agents and will give a turbid solution at this point.
reduce chromium, as indicated by the green color of the
Newer chemically resistant-type lead chromate type pigments (silica
solution. Cool. Neutralize with saturated Na CO solution and
2 3
encapsulated) cannot be decomposed by the procedures described in this
add a slight excess. Transfer to a 250-mL volumetric flask,
method. Pigments of this type may require treatment with strong alkali
dilute to the mark with distilled water, and mix. Filter without
hydroxide or hydrofluoric acid.
Also,iftrivalentantimonyhasbeenusedinmanufacturingtheproduct,
washing through a dry filter paper, discarding the first 10 to 15
pentavalent antimony may be present which would interfere in the
mL.
determination of lead chromate.
14.2 Take a 200-mL aliquot of the filtrate, neutralize with
HCl (1+1), and add 10 mLexcess. Heat to boiling and boil for
5 min. To the gently boiling solution, add 15 mL of BaCl
6 2
Sections23and24under“CalculationofSubstancesOtherthanInsolubleLead
solution dropwise with constant stirring. Digest on a steam
Compounds”shouldbereadcarefullybeforeproceedingwiththeanalysesdescribed
in Sections 10 to 22. bath for 2 h. Filter through an ignited tarred Gooch crucible,
D126 − 87 (2012)
wash with HCl (1+99), and finally with hot water. Dry at 105 17.2 Rinse the sulfide precipitate into the original beaker
to 110°C, ignite at 900°C, and wei
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