ELUTION FACTORS OF SYNTHETIC OXOTRIACYLGLYCEROLS AS AN AID IN IDENTIFICATION OF PEROXIDIZED NATURAL TRIACYLGYLCEROLS BY REVERSE-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ELECTROSPRAY MASS-SPECTROMETRY

Selected elution factors were determined for model oxotriacylglycerols as an aid in identification of the peroxidation products of natural t riacylglycerols by reverse-phase high-performance liquid chromatograph y (HPLC) with electrospray mass spectrometry (LC/ES/MS). For this purp ose synthetic triacylglycerols of known structure were converted to hy droperoxides, hydroxides, epoxides, and core aldehydes and their dinit rophenylhydrazones by published procedures. The oxotriacylglycerols we re resolved by normal-phase thin-layer chromatography and reverse-phas e HPLC, and the identities of the oxotriacylglycerols confirmed by LC/ ES/MS. Elution factors of oxotriacylglycerols were determined in relat ion to a homologous series of saturated triacylglycerols, ranging from 24 to 54 acyl carbons, and analyzed by reverse-phase HPLC, using a gr adient of 20-80% isopropanol in methanol as eluting solvent and an eva porative light-scattering detector. It was shown that the elution time s varied with the nature of the functional group and its regiolocation in the triacylglycerol molecule. A total of 31 incremental elution fa ctors were calculated from chromatography of 33 oxygenated and nonoxyg enated triacylglycerol species, ranging in carbon number from 36 to 54 and in double-bond number from 0 to 6.