ASTM_D_3634_-_21.pdf

Designation:D363421Standard Test Method forTrace Chloride Ion in Engine Coolants1This standard is issued under the fixed designation D3634;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 indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the determination of chlorideion in engine coolants in the range from 5 ppm to 200 ppm inthe presence of up to 0.6 weight%mercaptobenzothiazole.1.2 Other materials that react with silver ion will interfere.1.3 Chloride in engine coolants containing an aryltriazoleinstead of mercaptobenzothiazole can be determined directlyby this test method without pretreatment with hydrogen per-oxide.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazards statements are given in Section 7.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1176 Practice for Sampling and Preparing Aqueous Solu-tions of Engine Coolants orAntirusts for Testing PurposesD1193 Specification for Reagent WaterE200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical Analysis2.2 Manufacturing Chemists Association Document:3MCA Chemical Safety Data Sheet SD-53 Properties andEssential Information for Safe Handling and Use ofHydrogen Peroxide3.Summary of Test Method3.1 The sample is first treated at a pH of 12 to 13 withaqueous hydrogen peroxide to oxidize the mercaptobenzothi-azole to soluble,noninterfering sulfonate.The treated sample isdissolved in glacial acetic acid and titrated potentiometricallywith dilute standard silver nitrate solution.Since the solubilityof silver chloride in this system is sufficient to preventobtaining a suitable inflection at the very low limit of the testmethod,some chloride is deliberately added to the glacialacetic acid solvent and then corrected for by a blank titration.4.Significance and Use4.1 This test method permits the determination of very lowlevels of chloride ion in engine coolants containing thecommon corrosion inhibitor,mercaptobenzothiazole,or relatedmercaptans,which would normally interfere with the titrationby also forming insoluble silver salts with silver nitrate.5.Apparatus5.1 Manual Titrations:5.1.1 pH MeterAn expanded scale pH meter which can beread to 1 mV or 2 mV is desirable but not required.A silverbillet indicator electrode4and glass reference electrode5areused for the chloride titration.The silver electrode should be1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and Related Fluids and is the direct responsibility of SubcommitteeD15.04 on Chemical Properties.Current edition approved Nov.1,2021.Published November 2021.Originallyapproved in 1977.Last previous edition approved in 2015 as D3634 99(2015).DOI:10.1520/D3634-21.2For 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.3Available from American Chemistry Council(ACC),700 Second Street,NE,Washington,DC 20002,https:/.4The sole source of supply of the Silver Billet Electrode known to the committeeat this time is Fisher Scientific(,Catalog No.13-620-122).If youare aware of alternative suppliers,please provide this information to ASTMInternational Headquarters.Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.5The sole source of supply of the reference electrode known to the committee atthis time is Fisher Scientific(,Catalog No.13-620-216).If youare aware of alternative suppliers,please provide this information to ASTMInternational Headquarters.Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established