ASTM_D_4653_-_87_2020.pdf

Designation:D465387(Reapproved 2020)Standard Test Method forTotal Chlorides in Leather1This standard is issued under the fixed designation D4653;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 is intended for use in determining totalchlorides in mineral tanned leather.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:2D2813 Practice for Sampling Leather for Physical andChemical Tests3.Significance and Use3.1 This test method is used to determine amount of solublechlorides in leather.4.Apparatus4.1 Volumetric Flask,250 mL.5.Reagents5.1 Acetic Acid Solutions5 or 10%by volume.5.2 Methyl Orange0.02%solution in 50%alcohol.5.3 Ammonium Hydroxide Solution,(0.1 N).5.4 Silver Nitrate,Standard Solution,(0.1 N).5.5 Potassium Chromate Solution,5%.6.Sampling,Test Specimens and Test Units6.1 The test specimen shall consist of 1 g of leather from thecomposite sample in accordance with Practice D2813.6.2 Two specimens from the composite sample shall betested.7.Procedure7.1 Weigh the specimen to the nearest milligram and recordthe value as W.Transfer the specimen to a 250 mL volumetricflask and add 200 mL of 0.1 N ammonium hydroxide solution.Immerse the flask up to the neck in a bath of boiling water.Thoroughly wet all particles by occasional swirling.After 2 h,cool the flask to room temperature and make the flask up tovolume with distilled water,shake and without delay filterthrough a folded filter paper.7.2 Discard the first 20 to 25 mL of the filtrate.Pipette 200mL of the filtrate into a 600 mL beaker,add a few drops ofmethyl orange indicator and neutralize with 5%acetic acid toan orange color.Add 2 to 3 mL of 5%potassium chromate andtitrate the solution with 0.1 N silver nitrate.Record themillilitre of silver nitrate asA.Titrate 200 mLof distilled watercontaining a few drops of methyl orange indicator and 2 to 3mL of 5%potassium chromate with 0.1 N silver nitrate as ablank and the millilitre of silver nitrate used and recorded as B.8.Calculation of Results8.1 Calculate the percent total chlorides as follows:total chlorides,%5A 2 B!N/W 30.03553250/2003100(1)where:A=millilitres of standard silver nitrate used for titrating thesample,B=millilitres of standard silver nitrate used for titrating theblank,N=normality of the standard silver nitrate,andW=weight of the specimen.8.2 The total chlorides in the sample for test shall be theaverage of the test result obtained from the specimens tested.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.06 on Chemical Analysis.Current edition approved April 1,2020.Published April 2020.Originallyapproved in 1987.Last previous edition approved in 2015 as D4653 87(2015).DOI:10.1520/D4653-87R20.2For 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 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.9.Report9.1 Unless otherwise specified in the detail specification,theresult shall be reported to the nearest 0.1%.10.Precision and Bias10.1 This test method is adopted from the procedures of theAmerican Leather ChemistsAssociation where it has long beenin use and where it was approved for publication before theinclusion of precision and bias statements were mandated.Theoriginal inter-laboratory test data is no longer available.Theuser is cautioned to verify by the use of reference materials,ifavailable,that the p