Procedures are described for rapid lipase hydrolysis of triglycerides, isolation of the hydrolytic products by TLC and their conversion to methyl esters and fatty acid analysis by GLC. The techniques are applicable to a few mg of triglycerides or fats. Examples of data obtained with purified triglycerides i~dieate that the specific action of pancreatic lipase for the 1,3 ester groups is nearly absolute and the technique may be used as a criterion of purity of di-and tri-aeid triglycerides. Ca. 83% of the palmitie but only 10-12% of stearic and Cls unsaturated acids of commercial lard occur in 2-position.

A simple and convenient method for the quantitative preparation of methyl esters of fatty acids from glyceride fats and oils is described. The procedure, using potassium methylate as catalyst and a heating interval of 2 min at 65C in a closed vial, is applicable to fats containing both low and high molecular weight fatty acids such as butteroil. The methyl esters of samples ranging from a few mg to 30 mg are isolated by CS2 extraction and a TLC technique. A similar procedure using sulfuric acid in methanol as catalyst is described for the conversion of free fatty acids to methyl esters. For the routine analysis by GLC of fats and oils such as lard, tallow, soybean, cottonseed oil or butteroil, no isolation of the methyl ester is required. A CS2 extraction carried out in the reaction vial allows the GLC analysis immediately after the reaction period (2 min).

SummaryMethyl esters were prepared from cholesteryl esters, phospholipids, and glycerides in substantially quantitative yields by methanolysis with large excess of sodium or potassium methoxide in absolute methanol.A silicic acid chromatographic adsorption column technique was described, which was effective in separating methyl esters from unsaponifiables such as sterols, pigments, etc., and free acids.Conditions for complete methanolysis of glyceride fats and oils requiring only 5 min. of reflux time were described.Quantitative conversion of fatty acids to methyl esters was accomplished by direct esterification with absolute methanol containing 4% HCL or H2SO4 and by methylation with diazomethane.

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