1、Designation:D 1821 95Standard Test Method forInorganic Chlorides in Askarels1This standard is issued under the fixed designation D 1821;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses
2、 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 determination of inorganicchloride ions in askarels,in the range 0.02 to 100 ppm.1.2 This standard does not purport to address all
3、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 practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in 8.2.2.Referenced Doc
4、uments2.1 ASTM Standards:D 1193 Specification for Reagent Water23.Summary of Test Method3.1 Chloride ion is determined by potentiometric titration inan essentially nonaqueous medium.4.Significance and Use4.1 In the presence of water,chlorides can ionize.Theircorrosive action can then be detrimental
5、to the life of theapparatus in which the askarel is used.4.2 Many askarels contain polychlorinated biphenyls(PCBs).Manufacture and sale of PCBs has been prohibited byFederal regulation in the United States since 1978.Theconditions for continued use and the handling and disposal ofPCBs are also regul
6、ated.Users of this and other methods ofmeasuring the properties of askarels containing PCBs areresponsible for following applicable Federal,state,and localregulations.5.Interferences5.1 Other halogens interfere but will not normally beencountered in making this test.6.Apparatus6.1 Electrometric Titr
7、imeter.36.2 Electrode System for TitrimeterThe most satisfactoryelectrode system,with respect to length of life and ease ofmaintenance,is a silver-glass system.4Other electrodes thathave given satisfactory results are silver-silver chloride5andsilver(wire or billet)-mercurous sulfate,prepared as fol
8、lows:6.2.1 Dismantle the internal element from the salt bridgetube of a standard calomel reference electrode.Discard thesaturated potassium chloride(KCl)solution from the tube,andclean out the mercurous chloride(Hg2Cl2)and mercury fromthe internal element.Clean the parts thoroughly.Add sufficientnew
9、 clean mercury to the internal element to make contact withelectrode wire,and repack the chamber of the internal elementwith mercurous sulfate(Hg2SO4)moistened with 0.5 Mpotassium sulfate(K2SO4)solution.Seal the chamber withnonabsorbent cotton.Fill the salt bridge tube with 0.5 MK2SO4solution and re
10、assemble the units.6.2.2 The life of the silver-mercurous sulfate electrode islimited.It should be repacked when the mercurous sulfate turnsfrom white to brown.6.3 BuretMicroburet,1.0-mL capacity.66.4 MagneticStirrer,withglass-coveredorTFE-fluorocarbon-coated stirring bar.7.Reagents and Materials7.1
11、 Purity of ReagentsUse reagent grade chemicals in alltests.Unless otherwise indicated,it is intended that all reagentsshall conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society,wheresuch specifications are available.7Other grades may be used,provided
12、it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Purity of WaterUse reagent grade water conformingto Specification D 1193,unless otherwise specified.In addi-tion,the water shall be chloride-free,as detecte
13、d by this test.7.3 Acetone,containing no titratable chloride.1This test method is under the jurisdiction of ASTM Committee D-27 onElectrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-mittee D27.06 on Chemical Test.Current edition approved June 15,1995.Published August 19
14、95.Originallypublished as D 1821 60 T.Last previous edition D 1821 84(1989).2Annual Book of ASTM Standards,Vol 10.01.3Beckman Model GS,Beckman Model G,Leeds&Northrup Catalog No.7664,and the Fisher Titrimeter have been found satisfactory for this purpose.4Beckman silver billet electrode No.39261 and
15、glass electrode No.40498 havebeen found satisfactory for this purpose.5Obtainable from Fisher Scientific Co.6Fisher Catalog No.20-110 and Scientific Glass Apparatus Co.No.JM-570burets have been found satisfactory for this purpose.7“Reagent Chemicals,American Chemical Society Specifications,”Am.Chemi
16、-cal Soc.,Washington,DC.For suggestions on the testing of reagents not listed bytheAmerican Chemical Society,see“Reagent Chemicals and Standards,”by JosephRosin,D.Van Nostrand Co.,Inc.,New York,NY,and the“United StatesPharmacopeia.”1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTICE:Thisstandardhaseitherbeensupersededandreplacedbyanewversionordiscontinued.ContactASTMInternational(www.astm.o
