ASTM_D_1106_-_21.pdf

Designation:D110621Standard Test Method forAcid-Insoluble Lignin in Wood1,2This standard is issued under the fixed designation D1106;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 method3covers the determination of theacid-insoluble lignin content of wood.1.2 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.Specific precautionary statements are given in 6.1.1.3 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:4D1107 Test Method for Ethanol-Toluene Solubility of Wood3.Principle of Method3.1 When wood is treated with strong acids the carbohy-drates are hydrolyzed,leaving an insoluble residue which isdetermined as acid-insoluble lignin.Since some of the woodextractives(oils,resins,fats,waxes,tannins,gums,and starch)would remain insoluble with the lignin,these are first removedby extraction with suitable solvents.The 72%sulfuric acidmethod for lignin contains two and sometimes three prelimi-nary extractive treatments of the wood,namely:(1)withethanol,to remove the catechol tannins;(2)with ethanol-toluene solution,to remove the resins,oils,fats and waxes;and(3)with hot water,to remove the remaining water-solublematerials.3.2 The ethanol extraction is necessary in analysis of woodshigh in tannin;that is,oak,chestnut,redwood,etc.It has notbeen shown necessary in the more common pulpwoods,suchas the various species of spruce,pine,fir,hemlock,poplar,birch,beech,and maple.It is recommended that for thesewoods the alcohol extraction be omitted unless it is desirablefor a special purpose.In analysis of woods not listed,thedesirability of the alcohol extraction depends upon the purposeof the analysis and the report should state whether or notethanol extraction was used.4.Significance and Use4.1 Wood contains approximately 20 to 30%lignin.Re-moval of the lignin is the primary objective of pulping andbleaching procedures.Determination of the lignin contentprovides information for the evaluation and application ofthese processes.5.Apparatus5.1 Extraction ApparatusA compact form of Soxhlet ex-traction apparatus,with ground-glass joints,is preferable.Theapparatus shall consist of the following items:5.1.1 Soxhlet Extraction Flask,having a capacity of 250mL.5.1.2 Soxhlet Extraction Tube,45 to 50 mm in insidediameter,having a capacity to the top of the siphon ofapproximately 100 mL and a siphon tube approximately 55mm in height.Extraction tubes of these dimensions siphonmore rapidly than extractors with higher siphon tubes.5.1.3 Condenser,of the Hopkins inner-cooled type.5.1.4 Extraction Crucibles,of Alundum or fritted glass andof medium or fine porosity.5.2 Filtering CruciblesAlundum,porous porcelain,orfritted-glass crucibles(all of fine porosity),or Gooch crucibles1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.01 on Fundamental TestMethods and Properties.Current edition approved Feb.1,2021.Published March 2021.Originallyapproved in 1950.Last previous edition approved in 2013 as D1106 96(2013).DOI:10.1520/D1106-21.2This standard was originally based upon TAPPI standard Method T222-om-83,which has been replaced by T 222 om-15.3For further information on this test method the following references may beconsulted:Bray,M.W.,“Methods Used at the Forest Products Laboratory for the ChemicalAnalysis of Pulps and Pulpwoods,”Paper Trade Journal,Vol 87,No.25,December20,1928,p.29.Ritter,G.J.,Seborg,R.M.,Mitchell,R.L.,Industrial and EngineeringChemistry,Analytical Edition,Vol 4,1932,p.202.Ritter,G.J.,and Barbour,J.H.,Industrial and Engineering Chemistry,Analytical Edition,Vol 7,1935,p.238.4For 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.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