ASTM_D_6405_-_99_2014.pdf

Designation:D640599(Reapproved 2014)Standard Practice forExtraction of Tannins from Raw and Spent Materials1This standard is issued under the fixed designation D6405;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 practice covers extracting the tannin from raw andspent materials.The water extract obtained by this method isused to determine the tannin content of the original material.Analysis for total solids,soluble solids,and soluble non-tannins of the water extract from a material provides theinformation necessary to calculate the extractable tannin con-tent of that material.The types of materials typically analyzedby this practice are products of plants such as woods,barks,leaves,nuts,fruits,roots,etc.and any of a wide variety ofby-products(spent materials)from industrial processes utiliz-ing plant products.1.2 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.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:2D1517 Terminology Relating to LeatherD4903 Test Method for Total Solids and Water in VegetableTanning Material ExtractsD4904 Practice for Cooling of Analytical SolutionsD6401 Test Method for Determining Non-Tannins and Tan-nin in Extracts of Vegetable Tanning MaterialsD6402 Test Method for Determining Soluble Solids andInsolubles in Extracts of Vegetable Tanning MaterialsD6403 Test Method for Determining Moisture in Raw andSpent MaterialsD6404 Practice for Sampling Vegetable Materials Contain-ing Tannin2.2 ALCA Methods:A5 Extraction of Raw and Spent Materials33.Terminology3.1 Definitions:3.1.1 For definitions of general leather and tanning termsused in this practice refer to Terminology D1517.3.1.2 raw materialany of the various parts of plants thatare used as a source of vegetable tannins.3.1.3 spent materialplant tissue by-products from indus-trial processes which may contain significant quantities ofvegetable tannins.3.1.4 tanninan astringent substance found in the variousparts of plants such as bark,wood,leaves,nuts,fruits,roots,etc.3.1.5 vegetable tanninsmixtures of substances(naturalproducts)obtained from plant tissues by water extractionwhich have the chemical and physical properties necessary toconvert animal hides and skins into leather.4.Summary of Practice4.1 The sample of material to be analyzed for tannin contentis first brought to moisture equilibrium with the laboratoryatmosphere(that is,wet materials such as spent materials arefirst dried under ambient laboratory conditions)and thenground sufficiently to pass through a sieve.This ground sampleis then extracted with water in a steam-jacketed extractor.5.Significance and Use5.1 This practice provides a standard procedure for obtain-ing the water-soluble materials(including tannins)from anymaterial that can be prepared for and charged to the steam-jacketed extractor.The extraction solutions are then analyzedaccording to Test Methods D4903,D6401,and D6402.6.Apparatus and Reagents6.1 Sieve,with circular openings 1.27 cm(0.50 in.)indiameter.1This practice is under the jurisdiction of ASTM Committee D31 on LeatherThis test method has been adapted from and is a replacement for Method A5 of theOfficial Methods of the American Leather Chemists Association.Current edition approved Nov.1,2014.Published December 2014.Originallyapproved in 1999.Last previous edition approved in 2009 as D6405 99(2009).DOI:10.1520/D6405-99R14.2For 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 States1 6.2 Sieve,with circular openings of 2 mm diameter(U.S.Std.Sieve Series No.10).6.3 Glass Rods,soft glass stirring rods with rounded,fire-polished ends.6.4 Borosilicate Glass Wool,made of soft,pliable fibers.6.5 Steam-Jacketed,BorosilicateGlassExtractionApparatus,as described in Fig.1.This apparatus may need tobe special ordered and custom built by a laboratory glass-blowing manufacturer.6.6 Tubing,flexible,chemical and heat resistant tubing ofappropriate size and length to fit onto the outlet tubes of theext