ASTM_D_6016_-_06_2012.pdf

Designation:D601606(Reapproved 2012)Standard Test Method forDetermination of Nitrogen,Water Extractable in Leather1This standard is issued under the fixed designation D6016;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 covers quantitatively determining thewater extractable nitrogen in 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2868 Test Method for Nitrogen Content(Kjeldahl)andHide Substance Content of Leather,Wet Blue and WetWhiteD2876 Test Method for Water-Soluble Matter of Vegetable-Tanned LeatherD3495 Test Method for Hexane Extraction of LeatherD3790 Test Method for Volatile Matter(Moisture)ofLeather by Oven Drying2.2 Federal Standard:Federal Test Standard No.311,Method 6452 Nitrogen,Wa-ter Extractable33.Significance and Use3.1 This test method provides the means to determinenitrogen containing water extractable materials such as excessand loosely bound tannins,ammonium salts,and nitrates.4.Apparatus4.1 Volumetric Flask,1 L.4.2 Kjeldahl Apparatus,see Test Method D2868.5.Reagents5.1 See Test Method D2868.5.2 See Test Method D3495.5.3 See Test Method D2876.6.Procedure6.1 Follow the procedure for Test Method D3495.Saveextracted leather and follow the procedure in 7.1 only of TestMethod D2876.6.2 When 1 L has been collected,cool the litre flask withcontents to room temperature,readjusted up to 1 L withdistilled water and mixed thoroughly.Transfer 500 mL of thesolution to an 800-mL Kjeldahl flask.If using automatedKjeldahl instrumentation,sample size and quantity of reagentsmay need adjustment.Add 8 g of digestion catalyst(see TestMethod D2868)and 20 mL of sulfuric acid(specific gravity1.83)to the solution and the contents of the flask mixedthoroughly.6.3 Digest the mixture over a low heat source until allorganic matter is oxidized as indicated by the end of foamingand clearing of the solution.When foaming has ceased and thesolution has cleared,apply full heat to the mixture and continuedigestion for a minimum of 1 h.After digestion is complete,remove the flask from the heat,and allow to cool to roomtemperature.Then add 25 mLof 8%sodium thiosulfate and setaside the flask for 5 to 10 min with occasional stirring.6.4 Follow distillation and titration procedure in 7.3 of TestMethod D2868.7.Calculation7.1 Calculate the water extractable nitrogen in the specimenas follows:water extractable nitrogenmoisture2 free basis!,%(1)5A 3N 30.01432 3100W 31002 M!100!1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.06 on ChemicalAnalysis.Thistest method was developed from Federal Test Method Standard No.311,Method 6452 in cooperation with the U.S.Army Natick Research Development&Engineering Center,Natick MA and the Defense Personnel Support CenterDirectorate of Clothing and Textiles,Philadelphia PA.Current edition approved April 1,2012.Published April 2012.Originallyapproved in 1996.Last previous edition approved in 2006 as D6016 06.DOI:10.1520/D6016-06R12.2For 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 Superintendent of Documents,U.S.Government PrintingOffice,Washington,DC 20402.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 where:A=of standard acid(corrected for blank)required to titratethe specimen,mL,N=normality of the standard acid,W=weight of the specimen,g,andM=moisture content of the leather(see Test MethodD3790).8.Report8.1 The water extractable nitrogen in the specimen shall bethe average of the results obtained from the specimens tested,and shall be reported to the nearest 0.01%.Report individualresults utilized in obtaining the average.9.Precision and Bias9.1 See Test Method D2868 for information on precisionand bias.10.Keywords10.1 ammonium salts;leather;nitrates;nitrogen;tannins;water absorption;water extractableASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such right