ASTM_D_2942_-_02_2013.pdf

Designation:D294202(Reapproved 2013)Standard Test Method forTotal Acid Acceptance of Halogenated Organic Solvents(Nonreflux Methods)1This standard is issued under the fixed designation D2942;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 Department of Defense.1.Scope1.1 This test method covers the determination of the totalacid acceptance including amine and neutral type(alphaepoxide)stabilizers in halogenated organic solvents.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 and health practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2106 Test Methods for Determination of Amine AcidAcceptance(Alkalinity)of Halogenated Organic SolventsE200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical Analysis3.Summary of Test Method3.1 Test Method AThe total acid acceptance is determinedby the reaction of the sample with a known amount ofhydrochloric acid that has been dissolved in isopropyl alcohol.The excess acid remaining after the reaction with the acidacceptor is then back-titrated with a standardized solution ofsodium hydroxide.The total acid acceptance of the stabilizerscan be calculated and reported as weight%NaOH.3.2 Test Method BThe acid acceptor content is determinedby gas chromatography or another validated method such asdensity or refractive index and the acid acceptance is calculatedfrom the weight%acid acceptor.Techniques like density andrefractive index are generally suitable only for two-part sys-tems.The method for the determination of the acid acceptorshould be validated for the sample being analyzed to ensurethere is no interference,particularly from such things as oilsand reaction products when measuring acid acceptance ofproduct that is in use such as vapor degreasers.4.Significance and Use4.1 Solvents that have been depleted in stabilizer contentcan become acidic.Acids can cause corrosion to process andstorage equipment used for halogenated solvents.4.2 Halogenated organic solvents may contain amine type(alkaline,aqueous extractable)acid accepting additives,neutraltype(typically epoxide)acid accepting additives or both.Thistest method can determine the combined acid acceptance fromboth types of stabilizers.In addition,if the amine acidacceptance is determined by a separate procedure(see TestMethods D2106),the amount of neutral acid accepting stabi-lizers in a solvent can be calculated from the differencebetween combined and amine acid acceptance values.4.3 This test method may be used by producers and users toverify that a product is complying with acid acceptance productspecifications or by users to monitor the acid accepting abilityof a solvent in use.5.Test Method A5.1 Apparatus5.1.1 Iodine or Erlenmeyer Flasks 250-mL,with ground-glass stoppers.5.1.2 Burets,25-mL or 50-mL,graduated to 0.1 mL.5.1.3 Pipet,10-mL and 25-mL.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,1This test method is under the jurisdiction of ASTM Committee D26 onHalogenated Organic Solvents and Fire Extinguishing Agents and is the directresponsibility of Subcommittee D26.04 on Test Methods.Current edition approved Feb.1,2013.Published March 2013.Originallyapproved in 1971.Last previous edition approved in 2008 as D2942 02(2008).DOI:10.1520/D2942-02R13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Specification D1193.6.3 Bromophenol Blue Indicator Solution(1.0 g/L)Prepared by dissolving 1.0 g of bromophenol blue in a mixtureof 800 mL