DETERMINATION OF MOLECULAR-SPECIES OF OIL TRIACYLGLYCEROLS BY REVERSED-PHASE AND CHIRAL-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A method is described for the determination of molecular species of oil triacylglycerols. The method is based on the analytical separation of the enantiomeric sn-1,2- and sn-2,3-diacylglycerols, derived from triacylglycerols, by high-performance liquid-chromatography (HPLC) on a chiral column containing N-(R)4-(alpha-naphthyl)ethylamino-carbonyl-(S)-valine as stationary phase. Model triacylglycerol molecules comprising three known fatty acids were isolated from peanut oil and cottonseed oil by a combination of argentation-TLC and reversed-phase HPLC and submitted to partial chemical deacylation. The derived sn4,2(2,3)-diacylglycerols were analyzed and fractionated as 3,5-dinitrophenyl urethane derivatives by reversed-phase HPLC according to chainlength and unsaturation. From the sn4,2(2,3)-diacylglycerol composition and the diacylglycerol sn-1,2- and sn-2,3-enantiomer composition, the individual molecular species of four peanut oil triacylglycerols and one cottonseed oil triacylglycerol were identified and quantitated. The method can be applied to triacylglycerols of any other oil or fat.