1、Designation:C73894(Reapproved 2016)Standard Test Method forLead and Cadmium Extracted from Glazed CeramicSurfaces1This standard is issued under the fixed designation C738;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of la
2、st revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()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 glazed ceramicsurfaces.The
3、 procedure of extraction may be expected toaccelerate the release of lead from the glaze and to serve,therefore,as a severe test that is unlikely to be matched underthe actual conditions of usage of such ceramic ware.This testmethod is specific for lead and cadmium.1.2 The values stated in SI(metric
4、)units are to be regardedas the standard.The values given in parentheses are forinformation 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 appro-priate safety and health pra
5、ctices and determine the applica-bility of regulatory limitations prior to use.2.Summary of Test Method2.1 Lead and cadmium are extracted from the test article byleaching with 4%acetic acid for 24 h at 20 to 24C(68 to75F)and are measured by flame atomic absorption spectros-copy.3.Interferences3.1 Th
6、ere are no interferences when instrumental back-ground correction and light sources specific for lead andcadmium are used.4.Apparatus4.1 Atomic Absorption Spectrometer equipped with lightsources(hollow cathode or electrodeless discharge lamps)specific for lead and cadmium,instrumental backgroundcorr
7、ection,and a 4-in.(102-mm)single slot or Boling burnerhead.Digital concentration readout may be used.Use air-acetylene flame,instrumental background correction,and op-erating conditions recommended by instrument manufacturer.Using these conditions,characteristic concentration(concen-tration that giv
8、es 0.0044 absorbance)should be approximately(620%)0.2 and 0.45 ppm for Pb measured at 217.0 and 283.3nm,respectively.Characteristic concentration should be ap-proximately(620%)0.02 ppm for Cd.NOTE11 ppm=1 g/mL.4.2 Lead Lamp,set at 283.3 or 217.0 nm.4.3 Cadmium Lamp,set at 228.8 nm.4.4 Glassware of c
9、hemically resistant borosilicate glass,tomake reagents and solutions.Clean by rinsing with dilute nitricacid(10%by volume)followed by copious quantities of water.5.Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagen
10、ts shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.2Other grades may beused provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theacc
11、uracy of the determination.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean distilled water.5.3 Acetic Acid(4%by Volume)Mix 1 volume of glacialacetic acid with 24 volumes of water.5.4 Detergent WashUse detergent designed for washinghousehold dishes by hand
12、.Mix with lukewarm tap wateraccording to product instructions.5.5 Lead Nitrate Solution(1000-ppm Pb)Dissolve 1.598g of lead nitrate(Pb(NO3)2)in 4%acetic acid and dilute to 11This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares and Related Productsand is the direct res
13、ponsibility of SubcommitteeC21.03 on Methods for Whitewares and Environmental Concerns.This test methodwas developed jointly by the AOAC and ASTM,and adopted official final action bythe Association of Official Analytical Chemists(method 973.32 AOAC OffcialMethods of Analysis(1990)15th ed,AOAC Intern
14、ational,Arlington,VA.Current edition approved July 1,2016.Published July 2016.Originally publishedapproved in 1972.Last previous edition approved in 2011 as C738 94(2011).DOI:10.1520/C0738-94R16.2Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For su
15、ggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr
16、Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 L with 4%acetic acid.Commercially available standard leadsolutions may also be used.5.6 Hydrochloric Acid(1%by weight)Mix 1 volume ofconcentrated hydrochloric acid(HCl,sp gr 1.19)with 37volumes of water.5.7 Cadmium Solution(1000-ppm Cd)Dissolve 0.9273 gof anhydrous cadmium sulfate in approximately 250 mLof 1%HCl(see 5.6)and dilute to 500 mL with 1%HCl.Commer-cially available standard cadmium solutions may also be used.6.Proc
