1、Designation: D6016 06 (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 y
2、ear 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 stat
3、ed 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
4、 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-Ta
5、nned 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,Water Extractable33. Significance and Use3.1 This test method provides the means to determin
6、enitrogen containing water extractable materials such as excessand loosely bound tannins, ammonium salts, and nitrates.4. Apparatus4.1 Volumetric Flask,1L.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. Procedu
7、re6.1 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 t
8、hesolution to an 800-mL Kjeldahl flask. If using automatedKjeldahl instrumentation, sample size and quantity of reagentsmay need adjustment. Add8gofdigestion catalyst (see TestMethod D2868) and 20 mL of sulfuric acid (specific gravity1.83) to the solution and the contents of the flask mixedthoroughl
9、y.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 compl
10、ete,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 extractab
11、le nitrogen in the specimenas follows:water extractable nitrogen moisture2free basis!,%5A 3 N 3 0.014 3 2 3 100W 3100 2 M!100!(1)where:A = of standard acid (corrected for blank) required totitrate the specimen, mL,1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the
12、 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 leather; nitrates; nitrogen; tannins;water absorption; water extractableASTM Internatio
13、nal 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 rights, are entirely their
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15、 addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards
16、, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D6016 06 (2012)2
