1、Designation:D 1820 95Standard Test Method forHydrolyzable Chlorine Compounds in Chlorinated AromaticHydrocarbons(Askarels)1This standard is issued under the fixed designation D 1820;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the
2、 year 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 determination of hydrolyz-able chlorine compounds in chlorinated aromatic hydrocarbon
3、s(askarels).1.2 The values stated in metric units are to be regarded asthe standard.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 practices and de
4、termine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water23.Summary of Test Method3.1 This test method is a quantitative potentiometric titra-tion using silver nitrate in an essentially nonaqueous mediumto determ
5、ine chloride ions obtained after methanolic sodiumhydroxide hydrolysis of unstable chlorine compounds in chlo-rinated aromatic hydrocarbons of the askarel dielectric class.4.Significance and Use4.1 The measured chloride ion,reported as parts per millionin the askarel test specimen,is indicative of t
6、he relativestability of the askarel under prescribed conditions of test.4.2 Many askarels contain polychlorinated biphenyls(PCBs).Manufacture and sale of PCBs have been prohibitedby Federal regulation in the United States since 1978.Theconditions for continued use,handling,and disposal of PCBsare al
7、so regulated.Users of this and other methods of measur-ing the properties of askarels containing PCBs are responsiblefor following applicable Federal,state and local regulations.5.Interferences5.1 The presence of compounds containing hydrolyzablehalogen other than chlorine,that is,bromine and iodine
8、,willgive positive results,as will also any other foreign substancecapable of forming an insoluble compound with silver nitrate.Such materials would not normally be present in an askarel.5.2 The amount of chloride ions measured when the test isapplied to normally stable askarels is very small,rangin
9、g from0.1 to a few parts per million.Therefore,the test must be madein an area where the atmosphere is free from contaminatinginfluences,and it is essential to make a simultaneous blankdetermination.The value obtained on the blank will indicatethe degree to which the test environment,reagents,andgla
10、ssware are satisfactory for this type of testing.6.Apparatus6.1 Magnetic Stirrer,with speed control.6.2 Magnetic Stirring Bar,one-piece molded,TFEfluoro-carbon covered.6.3 Microburet,1.0-mL capacity,graduated in 0.01-mLdivisions.6.4 Electrode,Silver.3NOTE1Although the silver billet-glass electrode s
11、ystem is preferred,a silver electrode with a mercurous sulfate reference electrode may beused.However,a silver-silver chloride electrode system should not beused.6.5 Electrode,Standard Glass.36.6 Potentiometer,4suitable for use with the glass elec-trode.6.7 Water Bath,individual glass,150 mm in diam
12、eter and75 mm high to hold 600 mL of water conveniently.7.Reagents and Materials7.1 Purity of ReagentsUse reagent grade chemicals in alltests.Unless otherwise indicated,it is intended that all reagents1This test method is under the jurisdiction of ASTM Committee D-27 onElectrical Insulating Liquids
13、and Gasesand is the direct responsibility of Subcom-mittee D27.06 on Chemical Tests.Current edition approved June 15,1995.Published August 1995.Originallypublished as D 1820 60.Last previous edition D 1820 89a.2Annual Book of ASTM Standards,Vol 10.01.3Beckman Catalog No.39261 silver billet electrode
14、 and Catalog No.40498glass electrode have been found satisfactory for this purpose.4Beckman GS or Zeromatic and Leeds&Northrup pH meter have been foundsatisfactory for this purpose.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book
15、 of ASTM Standards.Copyright ASTMNOTICE:Thisstandardhaseitherbeensupersededandreplacedbyanewversionordiscontinued.ContactASTMInternational(www.astm.org)forthelatestinformation.shall conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society,wheresuch specif
16、ications are available.5Other grades may be used,provided 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 detected by this test.7.3 Acetone,Chloride-FreePrepare chloride-free acetoneby distillation from silver nitrate,as described in 7.5 formethanol.Deter
