ASTM_D_6401_-_99_2020.pdf

Designation:D640199(Reapproved 2020)Standard Test Method forDetermining Non-Tannins and Tannin in Extracts ofVegetable Tanning Materials1This standard is issued under the fixed designation D6401;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 This test method is intended for use in determining thequantity of soluble non-tannins and tannin in solutions oftannin extracts,water extracts of vegetable tanning materials,or tanning liquors.The method is applicable to the analysis ofliquid,solid,pasty,and powdered extracts and to extracts ofraw or spent materials.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses after SI units are forinformation only and are not considered 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,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:2D2617 Test Method for Total Ash in LeatherD3790 Test Method for Volatile Matter(Moisture)ofLeather by Oven DryingD4901 Practice for Preparation of Solution of Liquid Veg-etable Tannin ExtractsD4902 Test Method for Evaporation and Drying of Analyti-cal SolutionsD4903 Test Method for Total Solids and Water in VegetableTanning Material ExtractsD4905 Practice for Preparation of Solution of Solid,Pastyand Powdered Vegetable Tannin ExtractsD6402 Test Method for Determining Soluble Solids andInsolubles in Extracts of Vegetable Tanning MaterialsD6405 Practice for Extraction of Tannins from Raw andSpent Materials2.2 ALCA Method:A22 Non-Tannins and Tannin33.Terminology3.1 Definitions:3.1.1 soluble non-tanninsnon-volatile materials present intannin extracts and raw or spent materials that are dissolved orsuspended in water,are part of the soluble solids determined byTest Method D6402,and do not react with or bind to hidepowder when mixed as in this test method.3.1.2 tanninsnon-volatile materials present in tannin ex-tracts and raw or spent materials that are dissolved or sus-pended in water,are part of the soluble solids determined byTest Method D6402,and do react with or bind to hide powderwhen mixed as in this test method.4.Summary of Test Method4.1 An aliquot of the analytical solution prepared fromtannin extracts(Practices D4901 or D4905)or of the waterextract from raw or spent materials(Practice D6405)is driedovernight in a forced-air oven(Test Method D4902)and thesolid residue remaining is determined and defined as the totalsolids for that sample(Test Method D4903).Another aliquot ofthe same solution is passed through a specified filteringprocedure and the quantity of solid residue remaining in thefiltrate is determined and defined as the soluble solids for thatsample;the calculated difference between the total solids andthe soluble solids is defined as the insolubles for that sample(Test Method D6402).Another aliquot of the original analyti-cal solution or water extract is mixed with a prepared hide1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.01 on Vegetable Leather.Thismethod has been adapted from,and is a replacement for,MethodA22 of the OfficialMethods of the American Leather Chemists Association.Current edition approved Dec.1,2020.Published December 2020.Originallyapproved in 1999.Last previous edition approved in 2016 as D6401 99(2016).DOI:10.1520/D6401-99R20.2For 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.3Official Methods of the American Leather Chemists Association.Availablefrom the American Leather Chemists Association,University of Cincinnati,P.O.Box 210014,Cincinnati,OH 45221-0014.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.1powder material,with the