1、Designation: C 872 89 (Reapproved 2005)Standard Test Method forLead and Cadmium Release from Porcelain EnamelSurfaces1This standard is issued under the fixed designation C 872; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the precise determination oflead and cadmium extracted by acetic acid from porcelainena
3、mel surfaces.1.2 Values stated in SI units are to be regarded as thestandard. Inch-pound units are given for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish ap
4、pro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 738 Test Method for Lead and Cadmium Extracted fromGlazed Ceramic SurfacesD 1193 Specification for Reagent Water3. Summary of Test Method3.1 The
5、 lead and cadmium extracted from the article undertest by acetic acid at 20 to 24C (68 to 75F) after 24 h ofleaching are measured by atomic absorption spectrophotometryusing a specific hollow cathode lamp for lead and cadmiumrespectively.4. Significance and Use4.1 The determination of lead and cadmi
6、um release fromporcelain enamel surfaces was formerly of interest only tomanufacturers of porcelain enamel cookware and similar foodservice products. Food contact surfaces of these container-typeproducts have been evaluated using a test procedure similar toTest Method C 738. Recently, however, there
7、 has been a needto measure lead and cadmium release from flat or curvedporcelain enamel surfaces that are not capable of beingevaluated by a test similar to Test Method C 738.5. Interferences5.1 Since a specific hollow cathode lamp for lead andcadmium is used, there are no interferences.6. Apparatus
8、6.1 Atomic Absorption Spectrophotometer, equipped with a102-mm (4-in.) single slot or Boling burner head and digitalconcentration readout attachment (DCR) if available.3Thisinstrument should have a sensitivity of about 0.5 mg/L of leadfor 1 % absorption and a sensitivity of about 0.03 mg/L ofcadmium
9、 for 1 % absorption. The operating conditions asspecified in the instrument manufacturers analytical methodsmanual shall be used.NOTE 1ppm, mg/L, and g/mL are equivalent units.6.2 Hollow Cathode Lead Lamp, with wavelength set at283.3 or 217.0 nm.6.3 Hollow Cathode Cadmium Lamp, with wavelength setat
10、 228.8 nm.6.4 Glassware of chemically resistant borosilicate glass, tomake reagents and solutions.6.5 Test Cell, suitable for the containment of the leachingsolution on a flat porcelain enamel surface. A cell that hasproved suitable for this purpose is shown in Fig. 1.7. Reagents7.1 Purity of Reagen
11、tsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may be1This test method
12、 is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.12 onMaterials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved Sept. 15, 2005. Published September 2005. Original-lyapproved in 1977. Last pr
13、evious edition approved in 1999 as C 872 89 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Perkin-El
14、mer model 303 and Jarrell-Ash model 82-546 have been foundsuitable for this determination.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standard
15、s for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.used provid
16、ed it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean distilled water (seeSpecification D 1193).7.3 Acetic Acid (4 %
17、by volume)Mix 1 volume of glacialacetic acid with 24 volumes of water.NOTE 2A reagent blank shall be run each time a 4 % acid solution isprepared.7.4 Detergent RinseAdd 15 g of suitable alkaline deter-gent5to 1 gal (3.79 L) of lukewarm tap water.7.5 Lead Nitrate Solution (1000 mg Pb/L)Dissolve 1.598
18、g of lead nitrate (Pb(NO3)2) in 4 % acetic acid and dilute to 1L with 4 % acetic acid. Commercially available standard leadsolutions may also be used.5A suitable detergent is Calgonite, manufactured by the Calgon Corp., Box1436, Pittsburgh, PA 15230, and is available in most supermarkets.Metric Equi
19、valents for ApparatusDimensions (Fig. 1)in. mm18 3.214 6.438 9.5114 31.812532 45.2214 57.22.31 58.72.5 63.54 101.64116 103.2418 104.8512 139.7FIG. 1 Suitable Test CellC 872 89 (2005)27.6 Hydrochloric Acid (1 % by weight)Mix 1 volume ofconcentrated hydrochloric acid (HCl sp gr 1.19) with 37volumes of
20、 water.7.7 Cadmium (1000 mg Cd/L)Dissolve 0.500 g of cad-mium metal in 250 mL of hot 1 % HCl (see 7.6), cool, anddilute to 500 mL with 1 % HCl. Commercially availablestandard cadmium solutions may also be used.8. Samples8.1 Test SpecimensSpecimens may be cut from produc-tion parts or may be prepared
21、 on metal blanks under productionconditions. Tests may be made on finished parts where flathorizontal surfaces are available.8.2 SizeThe size of the test area shall be approximately 26cm2(4 in.2).9. Procedure9.1 Preparation of SampleTake, at random, three identi-cal units and cleanse each with the d
22、etergent rinse. Then rinsewith tap water followed by distilled water. Dry the specimensand fit into a suitable test cell similar to that shown in Fig. 1,or place a weighted cell onto a flat surface of a production part.Fill each unit with 4 % acetic acid, with a maximum of 40 mLfor each 6.45 cm2(1 i
23、n.2) of exposed surface. Record thevolume of acid for each unit in the sample. Cover each unitwith clear, colorless glass plate to prevent evaporation of thesolution, avoiding contact between the cover and surface of theleaching solution, and expose to normal laboratory light for 8to 10 h during the
24、 leaching period. Let the solution stand for 24h at room temperature (20 to 24C (68 to 75F).9.2 Preparation of Standards:9.2.1 Lead StandardsDilute lead nitrate solution (see 7.5)with acetic acid (see 7.3) to obtain working standards havingfinal concentrations of 0, 5, 10, 15, and 20 mg Pb/L.9.2.2 C
25、admium StandardsDilute cadmium stock solution(see 7.7) with acetic acid (see 7.3) to obtain working standardshaving final concentrations of 0.0, 0.3, 0.5, 1, 1.5, and 2.0 gCd/mL.9.3 Determination of Lead by Atomic AbsorptionStir thesample (leaching) solution and pour off a portion into a cleanflask.
26、 Using the atomic absorption spectrophotometer (6.1) andhollow cathode lamp (6.2), concomitantly determine the ab-sorbance of the lead working standards (9.2.1) and sample(leaching) solutions, diluting the latter with 4 % acetic acid ifrequired (if solution contains over 20 mg/L). Concentratesamples
27、 containing less than 1 ppm lead by accurately trans-ferring a minimum of 50.0 mL of solution to a 250-mL beakerand evaporating to dryness on a steam bath. Dissolve theresidue in 4 % acetic acid by adding exactly 0.1 volume ofsolution taken for concentration, cover with a watch glass, andswirl to co
28、mplete dissolution. Prepare a standard curve ofabsorbance versus concentration (mg/L). Determine the leadcontent (mg Pb/L) of sample (leaching) solution from thestandard curve.NOTE 3If a digital concentration readout is used, the standard curveis not necessary. However, standards bracketing the solu
29、tion under testshould be used.9.4 Determination of Cadmium by Atomic AbsorptionSpectrophotometryProceed as in 9.3 using the cadmiumhollow-cathode lamp (see 6.3) and cadmium standards (see9.2.2). If the sample (leaching) solutions contain more than 2mg Cd/L, dilute with 4 % acetic acid. Concentrate s
30、amplescontaining less than 0.1 mg/L as in 9.3.10. Report10.1 Report the type of units tested, the volume of acidused, and the lead and cadmium, respectively, leached inmicrograms per millilitre for each unit tested.NOTE 4As indicated in Section 1, this procedure covers the extractionand measurement
31、of lead and cadmium. It is general in that it does notrecommend specific sample unit types. For special end uses, as forexample, process control or interlaboratory testing, a specific size and typeof sample unit should be used.11. Precision and Bias11.1 Precision of the analytical method for a singl
32、e ormultiple operator within a single laboratory is within thesensitivity of the atomic absorption spectrophotometer.11.2 The precision and bias between laboratories is depen-dent upon the ability to obtain representative samples of thestatistical universe being sampled.ASTM International takes no p
33、osition respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsib
34、ility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to
35、ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the addre
36、ss shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 872 89 (2005)3
