ASTM_D_4370_-_01_2017.pdf

Designation:D437001(Reapproved 2017)Standard Test Methods forAcid and Base Milliequivalent Content of Electrocoat Bath1This standard is issued under the fixed designation D4370;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.1.Scope1.1 These test methods cover the determination of acid andbase milliequivalent contents of anodic and cathodic electro-coat baths and their ultrafiltrates.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 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:2D1193 Specification for Reagent Water3.Summary of Test Methods3.1 Specimens are titrated with standard acid and alkalisolutions respectively.Alternative procedures are given fordetermining acid and base concentrations potentiometrically orusing a pH meter.4.Significance and Use4.1 The acid and base concentrations are a measurement ofthe titratable acidic and alkaline components in the electrocoatbaths.These measurements are used for research,production orelectrocoat bath process control.5.Apparatus5.1 Automatic Potentiometric Titrator with Stirrer andRecorder,any model.5.2 Analytical Balance,with sensitivity of 0.1 mg.5.3 pH Meter,any model.5.4 Glass and Saturated Calomel Electrodes.5.5 Syringes,5-mL disposable.6.Reagents6.1 Purity of ReagentsReagent 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.3Other grades may be used,provided it is ascertained that thereagent is of sufficiently high purity to permit its use withoutlessening the accuracy of the determination.6.2 Purity of WaterReferences to water shall be under-stood to mean water conforming to Type II of SpecificationD1193.6.3 Potassium Hydroxide Solution in Methanol,0.1NPrepare by dissolving 5.6 g of potassium hydroxide(KOH)pellets in 1 L of methanol.Standardize against NIST standardreference material of acid potassium phthalate No.84 using anautomatic potentiometric titrator4to a given end point or,alternatively,to a phenolphthalein end point.6.4 Hydrochloric Acid Solution,0.1 NPrepare by mixingabout 8.50 mL of concentrated hydrochloric acid(HCl)(1.19sp gr)into a mixture of 600 mL water and 400 mL methanol.Standardize against 0.1 N potassium hydroxide solution(see6.3).1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.21 on Chemical Analysis of Paints and PaintMaterials.Current edition approved Dec.1,2017.Published December 2017.Originallyapproved in 1984.Last previous edition approved in 2012 as D4370 01(2012).DOI:10.1520/D4370-01R17.2For 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.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions 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.4Svehla,G.,Automatic Potentiometric Titration,Pergamon Press,1978,p.187.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 in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 6.5 1,3-Propanediol(Propylene Glycol)(PG).6.6 Tetrahydrofuran(THF).6.7 Reference pH Standard SolutionsCommercial stan-dards of pH 4.0,7.0,and 10.0.7.Sampling and Sample Preparation7.1 The sample should be obtained while the electrocoa