1、Designation:D597420Standard Test Methods forFatty and Rosin Acids in Tall Oil Fractionation Products byCapillary Gas Chromatography1This standard is issued under the fixed designation D5974;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revi
2、sion,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 These test methods cover the determination of theamounts of the individual fatty acids and rosin acids inf
3、ractionated tall oil products,using capillary gas chromato-graphic separation of the volatile methyl esters of these acids.1.2 Four methods for forming the methyl esters,and twomethods for determining the amounts of the individual fattyacids and rosin acids are described.1.2.1 The classic method for
4、 the formation of methyl estersis through the use of diazomethane,but diazomethane is ahazardous and toxic material,and so is no longer the preferredreagent.The use of diazomethane is detailed in the Appendix.Methyl esters may be formed through the use of tetramethyl-ammonium hydroxide(TMAH),trimeth
5、ylphenylammoniumhydroxide(TMPAH),or N,N-dimethylformamide dimethylacetal(DMF-DMA).1.2.2 The two methods for determining the amount of theindividual fatty acids and rosin acids are the“internal standard”method,which yields absolute values,and the“area percent”method,which yields relative values.1.3 T
6、his 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.1.4 This
7、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
8、)Committee.2.Referenced Documents2.1 ASTM Standards:2D509 Test Methods of Sampling and Grading RosinD804 Terminology Relating to Pine Chemicals,IncludingTall Oil and Related ProductsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use
9、3.1 Tall oil fractionated products derived from tall oil areimportant commercial materials,primarily composed of fattyacids and rosin acids,but also containing some neutral material(see Terminology D804).For many applications,it is necessaryto know the level of the individual fatty acids and rosin a
10、cidspresent in these products.Gas chromatography has proven tobe a useful tool for such determinations(see Test MethodsD509),and capillary chromatography,described in these testmethods,is considered to be the most effective gas chromato-graphic technique currently available.In particular situations,
11、other techniques may be more suitable than gas chromatogra-phy.For example,the presence of fatty acid esters in thesample would result in transesterification during the derivati-zation step that may affect the results.3.2 Due to hydrogen bonding,unmodified tall oil fatty acidsand rosin acids cannot
12、be volatilized at atmospheric pressurewithout undergoing decomposition.So,it is necessary toconvert the free acids to the more volatile and more stablemethyl esters,prior to chromatographic separation.3.3 These test methods describe four ways to preparemethyl esters.The classic method is through the
13、 use ofdiazomethane,but diazomethane is a hazardous and toxicmaterial,and so is no longer the preferred agent.The use ofdiazomethane is detailed in Appendix X1.3.3.1 TMAH causes isomerization of a samples di-andpolyunsaturated fatty acids,when it is used in even a slight1These test methods are under
14、 the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.34 on Pine Chemicals and HydrocarbonResins.Current edition approved Sept.1,2020.Published September 2020.Originallyapproved in 1996.Last previous editi
15、on approved in 2015 as D5974 15.DOI:10.1520/D5974-20.2For 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.Copyright AST
16、M 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 by the World Trade Organization Technical Barriers to Trade(TBT)Committee.excess.This leads to inaccurate results for the individual fattyacid components.TMAH should
