SILVER ION HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF THE TRIACYLGLYCEROLS OF CREPIS-ALPINA SEED OIL

The triacylglycerols of Crepis alpina oil were characterized because t his oil has a high concentration of crepenynic (cis-9-odadecen-12-ynoi c) acid, a fatty acid useful in the chemical synthesis of deuterated f ats for human metabolism studies. The triacylglycerols were separated from the crude oil by solid-phase extraction. Resolution, quantitation and isolation of the individual triacylglycerols were performed by si lver ion high-performance liquid chromatography on a commercial column , an acetonitrile in hexane isocratic mobile phase and flame-ionizatio n detection. Isolated triacylglycerols were identified by capillary ga s chromatography of their fatty acid methyl esters. Of the eleven elut ed triacylglycerols of Crepis alpina oil, 85% included 35% tricrepenyn oyl, 34% linoleoyldicrepenynoyl and 16% dilinoleoylcrepenynoyl glycero ls. Triacylglycerols eluted according to the numbers of alkene and alk yne bonds. Elution times, resolution and quantitation were reproducibl e over a three-month period. The flame-ionization detector response re quired no response factors for quantitation of the triacylglycerols pr esent in Crepis alpina oil. The silver ion chromatography system permi tted the identification of 95% of the triacylglycerols compared to 70% of the triacylglycerols previously identified with reversed-phase hig h-performance liquid chromatography.