ASTM C738-94(2011)
(Test Method)Standard Test Method for Lead and Cadmium Extracted from Glazed Ceramic Surfaces
Standard Test Method for Lead and Cadmium Extracted from Glazed Ceramic Surfaces
ABSTRACT
This test method details the standard and precise procedures for the determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The apparatus needed for this procedure include an atomic absorption spectrometer, lead and cadmium lamps, and glassware of chemical resistant borosilicate glass. The water, detergent wash, and reagents such as acetic acid, lead nitrate solution, hydrochloric acid, and cadmium solution should conform to chemical purity specified. Measurement procedures, precision, and bias are discussed thoroughly.
SCOPE
1.1 This test method covers the precise determination of lead and cadmium extracted by acetic acid from glazed ceramic surfaces. The procedure of extraction may be expected to accelerate the release of lead from the glaze and to serve, therefore, as a severe test that is unlikely to be matched under the actual conditions of usage of such ceramic ware. This test method is specific for lead and cadmium.
1.2 The values stated in SI (metric) units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, 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.
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Designation: C738 − 94(Reapproved 2011)
Standard Test Method for
Lead and Cadmium Extracted from Glazed Ceramic
Surfaces
This standard is issued under the fixed designation C738; 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.
1. Scope head. Digital concentration readout may be used. Use air-
acetylene flame, instrumental background correction, and op-
1.1 This test method covers the precise determination of
erating conditions recommended by instrument manufacturer.
leadandcadmiumextractedbyaceticacidfromglazedceramic
Using these conditions, characteristic concentration (concen-
surfaces. The procedure of extraction may be expected to
tration that gives 0.0044 absorbance) should be approximately
accelerate the release of lead from the glaze and to serve,
(620 %) 0.2 and 0.45 ppm for Pb measured at 217.0 and 283.3
therefore, as a severe test that is unlikely to be matched under
nm, respectively. Characteristic concentration should be ap-
the actual conditions of usage of such ceramic ware. This test
proximately (620 %) 0.02 ppm for Cd.
method is specific for lead and cadmium.
NOTE 1—1 ppm = 1 µg/mL.
1.2 The values stated in SI (metric) units are to be regarded
as the standard. The values given in parentheses are for 4.2 Lead Lamp, set at 283.3 or 217.0 nm.
information only.
4.3 Cadmium Lamp, set at 228.8 nm.
1.3 This standard does not purport to address all of the
4.4 Glassware of chemically resistant borosilicate glass, to
safety concerns, if any, associated with its use. It is the
make reagents and solutions. Clean by rinsing with dilute nitric
responsibility of the user of this standard to establish appro-
acid(10 %byvolume)followedbycopiousquantitiesofwater.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Reagents
5.1 Purity of Reagents—Reagent grade chemicals shall be
2. Summary of Test Method
used in all tests. Unless otherwise indicated, it is intended that
2.1 Lead and cadmium are extracted from the test article by
all reagents shall conform to the specifications of the Commit-
leaching with 4 % acetic acid for 24 h at 20 to 24°C (68 to
tee onAnalytical Reagents of theAmerican Chemical Society,
75°F) and are measured by flame atomic absorption spectros-
where such specifications are available. Other grades may be
copy.
used provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
3. Interferences
accuracy of the determination.
3.1 There are no interferences when instrumental back-
5.2 Purity of Water—Unless otherwise indicated, references
ground correction and light sources specific for lead and
to water shall be understood to mean distilled water.
cadmium are used.
5.3 Acetic Acid (4 % by Volume)—Mix 1 volume of glacial
4. Apparatus
acetic acid with 24 volumes of water.
4.1 Atomic Absorption Spectrometer equipped with light
5.4 Detergent Wash—Use detergent designed for washing
sources (hollow cathode or electrodeless discharge lamps)
household dishes by hand. Mix with lukewarm tap water
specific for lead and cadmium, instrumental background
according to product instructions.
correction, and a 4-in. (102-mm) single slot or Boling burner
5.5 Lead Nitrate Solution (1000-ppm Pb)—Dissolve 1.598
g of lead nitrate (Pb(NO ) ) in 4 % acetic acid and dilute to 1
3 2
ThistestmethodisunderthejurisdictionofASTMCommitteeC21onCeramic
Whitewares and Related Productsand is the direct responsibility of Subcommittee
C21.03 on Methods for Whitewares and Environmental Concerns. This test method
was developed jointly by theAOAC andASTM, and adopted official final action by Reagent Chemicals, American Chemical Society Specifications, American
the Association of Official Analytical Chemists (method 973.32 AOAC Offıcial Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Methods of Analysis (1990) 15th ed, AOAC International, Arlington, VA. listed by the American Chemical Society, see Analar Standards for Laboratory
Current edition approved March 1, 2011. Published March 2011. Originally Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
published approved in 1972. Last previous edition approved in 2006 as C738 – and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
94 (2006). DOI: 10.1520/C0738-94R11. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C738 − 94 (2011)
TABLE 1 Mean Value Required in a Large Lot for Failure Rate
L with 4 % acetic acid. Commercially available standard lead
1/10 000 with Coefficient of Variation 60 %
solutions may also be used.
Worstof6
Limit (ppm) Mean of 6
5.6 Hydrochloric Acid (1 % by weight)—Mix 1 volume of
(Mean of 1)
concentrated hydrochloric acid (HCl, sp gr 1.19) with 37
7 3.21 1.45
volumes of water. 5 2.29 1.03
2.5 1.15 0.52
5.7 Cadmium Solution (1000-ppm Cd)—Dissolve 0.9273 g
0.7 0.32 0.14
ofanhydrouscadmiumsulfateinapproximately250mLof1 % 0.5 0.23 0.10
0.25 0.11 0.05
HCl (see 5.6) and dilute to 500 mL with 1 % HCl. Commer-
cially available standard cadmium solutions may also be used.
6. Procedure
NOTE 2—Take a method control through entire procedure. Use a 6.4 Determination of Cadmium by Atomic Absorption
laboratory beaker with dimensions similar to ware being tested.
—Proceed as in 6.3 using the cadmium lamp (4.3) and
standards (6.2.2).
...
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