ASTM D4900-99 (2020) pdf free.Standard Test Method for Lignosulfonates (Sulfite Cellulose) in Tanning Extracts.
This test method is intended for use in detecting thepresence of lignosulfonates (sulfite cellulose) in extracts oftanning materials.
The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.
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 appropriate safety,health,and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This 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 TechnicalBarriers to Trade (TBT) Committee. The reaction with aniline of a tanning material extractspecimen is compared with that of a solution containinglignosulfonate and tanning material known to be free fromlignosulfonate.This test method is useful to detect possible adulterationof tanning material extract with cheap and inferior lignosulfonates.The sample shall be drawn as described in PracticeD6404.The specimen shall consist of 5 mL of a solution ofanalytical strength (4.0 g tannin per L), prepared as describedin Practices D4901,D4905, and Practice D6405.
This shall contain lignosulfonate(sulfite cellulose) in the proportion of 1 g total solids to 2000mL of solution, and as much tanning material, similar to and ofthe same type as that being tested but known to be free fromlignosulfonate,as will make up the solution to analyticalstrength.
Place the specimen in a test tube.Add 0.5 mL of aniline,and shake well.Add 2 mL of concentrated hydrochloric acid,and again shake mixture well.
If at least as much precipitate remains at the end of 15min as is obtained when the comparison solution is similarlytreated, the material shall be held to contain lignosulfonates(sulfite cellulose) and the fact shall be noted on the analysisreport.ASTM D4900 pdf download.
ASTM D4900-99 (2020) pdf free
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