1、Designation:D110596(Reapproved 2013)Technical Association of Pulp and Paper IndustryStandard Method T 12 os-75Standard Test Method forPreparation of Extractive-Free Wood1This standard is issued under the fixed designation D1105;the number immediately following the designation indicates the year ofor
2、iginal 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 the preparation of extractive-free wood and
3、is applicable to all North American woods.Extractives in wood consist of materials that are soluble inneutral solvents and that are not a part of the 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 thi
4、s standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in 4.2.2.Significance and Use2.1 Extractives are materials soluble in neutral solvents.They are not generally consider
5、ed part of the wood polymerstructure.These materials should be removed before anychemical analysis of the wood.Ethanol-benzene extractswaxes,fats,some resins,and portions of wood gums.Hotwater extracts tannins,gums,sugars,starches,and coloringmatter.3.Apparatus3.1 Soxhlet Extraction ApparatusA glass
6、 Soxhlet extrac-tion apparatus of suitable size for containing the sample,andfritted-glass or Alundum extraction thimbles of medium tocoarse porosity,will be required.Bags of cotton cloth of fineweave and thoroughly washed,of a suitable size to fit withinthe body of the extractor,are also satisfacto
7、ry in place of thethimbles.Alternatively,a small wad of cotton or a wire screenmay be placed in the discharge tube of the extractor and theentire body of the extractor filled with the wood sample.Athinwire screen disk placed over the top of the material will preventchanneling by the dripping condens
8、ate.4.Reagents4.1 Ethyl Alcohol(95%).4.2 Ethanol-Toluene MixtureMix 1.0 absolute ethanol and427 mL toluene.(WarningAvoid inhalation of vapors andcontact with skin.)5.Sample5.1 The sample shall consist of air-dry sawdust that hasbeen reduced by means of a Wiley mill so as to pass througha 250-m sieve
9、 and be retained on a 180-m sieve.6.Procedure6.1 Place a suitable quantity of the sample in the extractionthimble,being certain that the wood does not extend above thelevel of the top of the siphon tube.Extract for 4 h withethanol-toluene mixture in the Soxhlet extraction apparatus.Transfer the wood
10、 to a Bchner funnel,remove the excesssolvent with suction,and wash the thimble and wood withalcohol to remove the toluene.Return the wood to the extractorand continue the extraction with ethanol for 4 h,or longer ifnecessary,until the ethanol siphons over colorless.6.2 If the thimble is nearly full,
11、a Gooch crucible of suitablesize may be placed in the rim of the thimble to keep the sampletogether.Extraction with each solvent should be carried out ata rate of not less than four siphonings per hour.Remove thewood from the thimble,spread it out in a thin layer,and allowit to dry in the air until
12、free of alcohol.Transfer the material toa 7.5-L Erlenmeyer or Florence flask and extract successivelywith three 1-L portions of distilled water,heating the flask witheach change of water for 1 h in a hot-water bath at 100C.Thewater should be at boiling temperature before the addition ofthe wood and
13、the flask in the bath should be entirely sur-rounded by the boiling water.After the third extraction withwater is complete,filter on a Bchner funnel,wash with 500mL of boiling distilled water,and allow the extracted materialto become thoroughly dry in the air.7.Precision and Bias7.1 Statements of pr
14、ecision and bias are not applicable tothis method.8.Keywords8.1 extractive-free wood;wood1This 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 Aug.1,2013.Publ
15、ished September 2013.Originallyapproved in 1950.Last previous edition approved in 2007 as D1105 96(2007).DOI:10.1520/D1105-96R13.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 ASTM International takes no position respecting the validity
16、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 own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this
