Simultaneous determination of hydroperoxides of phosphatidylcholine, cholesterol esters and triacylglycerols by column-switching high-performance liquid chromatography with a post-column detection system.

A method for the simultaneous determination of hydroperoxides of phosphatidylcholines (PC), triacylglycerols (TG) and cholesterol esters (CE) has been developed. A sample was separated into a combined TG and CE hydroperoxides fraction and a PC hydroperoxides fraction on a short silica column. The fractions were introduced into an ODS column and another silica column by a valve-switching device. The PC hydroperoxides were monitored by a post-column detection system with diphenyl-1-pyrenylphosphine, and the TG and CE hydroperoxides were monitored by another switching device. With this system, the hydroperoxides were determined at the picomole level within 32 min. Their detection limits were 2-4 pmol at a signal-to-noise ratio of 3, and the relative standard deviations of the peak areas were 1.6-3.1%. This method was successfully applied to determine lipid hydroperoxides in human plasma.