ASTM_D_2800_-_92_1998.pdf

Designation:D 2800 92(Reapproved 1998)Standard Test Method forPreparation of Methyl Esters From Oils for Determination ofFatty Acid Composition by Gas-Liquid Chromatography1This standard is issued under the fixed designation D 2800;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(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method covers a rapid procedure for conver-sion of animal and vegetable fatty oils into methyl esters of thefatty acids suitable for analysis by gas-liquid chromatography.1.2 This test method is believed to be applicable to mostdrying oils used in the paint industry including linseed,soya,safflower,and cottonseed oils.Unsaturated oils with a tendencyto undergo alkaline isomerization or to polymerize in thepresence of boron trifluoride(BF3)may give erroneous results.Unsaponifiables are not removed.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.For specific hazardstatements,see 5.4 and Note 1.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water2D 1983 Test Method for Fatty Acid Composition by Gas-Liquid Chromatography of Methyl Esters3D 2245 Test Method for Identification of Oils and OilAcidsin Solvent-Reducible Paints4D 3457 Test Method for Preparation of Methyl Esters fromFatty Acids for Determination of Fatty Acid Compositionby Gas-Liquid Chromatography33.Summary of Test Method3.1 This test method is based upon a rapid saponification ofthe oil with methanolic sodium hydroxide followed by boilingthe soaps with BF3-methanol in the same vessel to convertquantitatively the fatty acids to methyl esters.The methylesters are floated out of the mixture upon addition of asaturated salt solution.3.2 Methyl margarate may be added quantitatively to the oilprior to saponification and methylation to serve as an internalstandard and check on the recovery of monomeric methylesters.For a discussion on the use of an Internal Standard seeTest Method D 3457.4.Significance and Use4.1 This test method provides a means by which animal orvegetable fats and oils are converted into their methyl esters sothat the fatty acids can then be analyzed by the use of TestMethod D 1983.5.Reagents and Materials5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests unless otherwise specified.Unless otherwiseindicated,it is intended that all reagents shall conform to thespecifications of the Committee on Analytical Reagents of theAmerican Chemical Society,where such specifications areavailable.5Other grades may be used,provided it is firstascertained that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the determi-nation.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Type IV of Specification D 1193.5.3 Boron Trifluoride,cylinder.65.4 Boron Trifluoride Reagent(125 g/L of Methanol)Add1 L of methanol to a 2-L Erlenmeyer flask and weigh on abalance.Place in an ice bath and slowly bubble borontrifluoride(BF3)gas from a tank through a glass tube until 125g are taken up.This operation should be performed in a goodfume hood,and the gas should not flow so fast that white fumesemerge from the flask.The BF3must be flowing through the1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D 01.32 on Drying Oils.Current edition approved March 15,1992.Published May 1992.Originallypublished as D 2800 70.Last previous edition D 2800 87.2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 06.03.4Annual Book of ASTM Standards,Vol 06.01.5Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.6The sole source of supply of the cylinder for boron trifluoride known to thecommittee at this time is Matheson Co.,Box 966,Joliet,IL.If you are aware ofalternative suppliers,please provide this information to ASTM Headquarters.Yourcomments will receive careful consideration at a meeting of the responsiblecommittee,1which you may attend.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprin