High Performance Liquid Chromatography of Hydroperoxides Formed by Autoxidation of Vegetable Oils

Abstract

Trilinoleoylglycerol (TL) was autoxidized at 37°C in the dark. Monohydroperoxides (MHP) obtained from the oxidized products were analyzed by high performance liquid chromatography (HPLC). Several peaks which appeared in the chromatogram were identified by infrared (IR), gas chromatography mass spectrometry (GC-MS) and enzymatic hydrolysis. Some positional and geometrical isomers of their hydroperoxy fatty acid components were separated using both absorption and reversed phase systems. Furthermore, 1-hydroperoxylinoleoyl-2, 3-dilinoleoylglycerol and 1, 3-dilinoleoyl-2-hydroperoxylinoleoylglycerol were partly separated by HPLC using an absorption system. MHP obtained from autoxidized corn oil, safflower oil and soybean oil were separated into some peaks by HPLC, although resolution into the individual isomers was incomplete. Whenoxidized oils were subjected to HPLC analysis directly, a linear relationship was observed between the peak areas of MHP and peroxide value in the range of 1050 meq/kg.