TLC as a tool for quantitative isolation of conjugated trienoic FA

Conjugated trienoic FA-alpha-eleostearic, beta-eleostearic, and punicic acids-were preferentially isolated in pure form from the total methyl esters of the respective oils by simple silica gel TLC using hexane/diethyl ether as the mobile phase (94:6). The subsequent saponification of the separated methyl ester fractions upon cooling at -20degreesC yielded individual acids in crystalline form. Melting points, conventional UV spectroscopy, and GLC confirmed the identity of the conjugated trienoic FA. The method finds potential application in bench-scale reaction optimization using pure FA and in the preparation of standard reference materials of these acids, as these oils are widely used in the coatings industry.