ASTM D49-83(2002)

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Designation:D49–83(Reapproved2002)
Standard Test Methods of
Chemical Analysis of Red Lead
ThisstandardisissuedunderthefixeddesignationD49;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Purity of Reagents
1.1 These test methods cover procedures for the chemical 4.1 Reagent grade chemicals shall be used in all tests.
analysis of red lead having the approximate formula Pb O Unlessotherwiseindicated,itisintendedthatallreagentsshall
3 4
(probably PbO ·2PbO). conform to the specifications of the Committee on Analytical
1.2 This standard does not purport to address all of the Reagents of the American Chemical Society where such
safety concerns, if any, associated with its use. It is the specifications are available. Other grades may be used pro-
responsibility of the user of this standard to establish appro- vided it is first ascertained that the reagent is of sufficiently
priate safety and health practices and determine the applica- high purity to permit its use without lessening the accuracy of
bility of regulatory limitations prior to use. the determination.
4.2 Unless otherwise indicated, references to water shall be
2. Referenced Documents
understood to mean reagent water conforming to Type II of
2.1 ASTM Standards: Specification D1193.
D50 Test Methods for Chemical Analysis of Yellow, Or-
5. Moisture
ange, Red, and Brown Pigments Containing Iron and
Manganese 5.1 Determine moisture content with a 2-g specimen in
D215 Practice for the ChemicalAnalysis ofWhite Linseed accordance with Method A of Test Methods D280. The
Oil Paints specimen is dried for2hat 105°C. The loss in weight is
D280 Test Methods for Hygroscopic Moisture (and Other considered as moisture.
Matter Volatile Under the Test Conditions) in Pigments
4 6. Organic Color
D1193 Specification for Reagent Water
D1208 Test Methods for Common Properties of Certain 6.1 Boil2gofthesamplewith25mLof95%ethylalcohol,
Pigments letsettle,decantthesupernatantliquid;boiltheresiduewith25
mL of distilled water and decant as before; boil the residue
D1301 Test Methods for ChemicalAnalysis ofWhite Lead
Pigments with 25 mL of diluted NH OH (1+4) and again decant. Boil
another 2-g portion of the sample with 25 mL of chloroform,
D1959 Test Method for Iodine Value of Drying Oils and
Fatty Acids let settle, and decant the supernatant liquid. If any one of the
abovesolutionsiscolored,organiccoloringmatterisindicated.
3. Treatment of Sample
If the solutions remain colorless, organic colors are probably
3.1 If the pigment is lumpy or not finely ground, grind it to absent.
a fine powder and mix thoroughly. Large samples may be
NOTE 1—If it is desired to test for organic colors resistant to the above
thoroughly mixed and a representative portion taken and
reagents, the test procedures described in the following books may be
powdered if lumpy or not finely ground. The sample in all
used, taking into account the nature of the pigment involved (1,2,3).
cases shall be thoroughly mixed before taking portions for
analysis.All samples shall be preserved in stoppered bottles or
containers.
1 5
These test methods are under the jurisdiction of ASTM Committee D01 on Reagent Chemicals, American Chemical Society Specifications, American
Paint and Related Coatings, Materials, and Applications and are the direct Chemical Society, Washington, DC. For suggestions on the testing of reagents not
responsibility of Subcommittee D01.31 on Pigment Specifications. listed by the American Chemical Society, see Analar Standards for Laboratory
Current edition approved Dec. 20, 1983. Published January 1984. Originally Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
published as D49–17T. Last previous edition D49–82. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 06.03. MD.
3 6
Annual Book of ASTM Standards, Vol 06.01. The boldface numbers in parentheses refer to a list of references at the end of
Annual Book of ASTM Standards, Vol 11.01. these test methods.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D49
7. Total Lead and Insoluble Matter temperature, dilute to exactly 1000 mL with the acetic acid
(1+3) and mix thoroughly. If preferred, the red lead solution
7.1 Treat1gofthesamplewith15mLofHNO (1+1)and
may be prepared separately for each titration, as follows:
sufficient H O to dissolve all PbO on warming. If any
2 2 2
Dissolve30gofthecrystallizedsodiumacetateand2.4gofKI
insolublematterispresent,add25mLofwater,boil,filter,and
in25mLoftheaceticacid(1+3),warminggentlyandstirring
wash with hot water. The insoluble matter contains free SiO
until a clear solution is obtained. Cool this solution to room
andshouldbeexaminedforBaSO andsilicates,ifappreciable.
temperature, dilute to 50 mL with the acetic acid solution
7.2 To the original solution or filtrate from the insoluble
(1+3), and mix thoroughly.
matter add 20 mLof H SO (sp gr 1.84) and evaporate to SO
2 4 3
8.2 Sodium Thiosulfate Solution (0.1N)—Dissolve 24.83 g
fumes. Cool, add 150 mLof water, and 150 mLof 95% ethyl
of sodium thiosulfate (Na S O ·5H O), freshly pulverized and
2 2 3 2
alcohol,letstand coldfor2h,filter,onaGoochcrucible,wash
driedbetweenfilterpaper,anddilutewithwaterto1litreatthe
with 95% alcohol, dry at 105 to 110°C, and weigh as PbSO .
temperatureatwhichthetitrationsaretobemade.Thesolution
Calculate to PbO.
isbestmadewithwell-boiledwaterfreefromCO ,orletstand
7.3 Red lead is rarely adulterated, but should the specimen
8 to 14 days before standardizing, as described in Section 5 of
contain soluble barium compounds, the PbSO obtained in 8.2
Test Method D1959.
will contain BaSO . In this case, precipitate the lead as sulfide
8.3 Starch Solution—Stir2to3gof potato starch with 100
from a slightly acid (HCl) solution, dissolve the PbS in hot
mL of salicylic acid solution (1%), and boil the mixture until
diluted HNO , and determine the lead as sulfate or chromate.
the starch is practically dissolved, then dilute to 1 L (Note 3),
7.4 If the specimen contains significant amounts of calcium
or prepare as described in 7.8.2 of Test Method D1959.
or magnesium, boil the HNO −H O solution (7.1) until all
3 2 2
theleadisconvertedintonitrateandthendeterminetheleadas
NOTE 3—Lead Peroxide—If the pigment contains an appreciable
amount of nitrite (nitrate has no effect on the method), leach out
PbCrO .
water-soluble matter as below, dry the residue and determine PbO as
7.5 If soluble barium, calcium, or magnesium are to be 2
above, calculating to basis of original specimen.
determined, precipitate the lead as sulfide from a slightly acid
solution (HCl), dissolve the PbS in hot diluted HNO , and
9. Procedure
determine the lead as sulfate. Boil the filtrate from the PbS to
9.1 Weigh1gofthe finely ground sample, transfer to a
expel H S, add a little bromine water to oxidize iron (if
200-mL Erlenmeyer flask, add 20 mL of water; then add as
present),boiltoexpelbromine,andprecipitatethebariumwith
quickly as possible 40 mL of the “red lead solution” at room
a few millilitres of H SO (1+3). Filter and weigh as BaSO .
2 4 4
temperature. If the sample is red lead that has been extracted
CalculatetoBaOorBaCO .TothefiltratefromtheBaSO add
3 4
from a paint or paste, in place of the water use 10 mL of a
NH OH in slight excess, filter off any precipitate of
mixture of 7 parts by volume of chloroform and 3 parts by
Fe(OH) +Al(
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