Electrochemical detection of phospholipid hydroperoxides in reverse-phase high performance liquid chromatography

Hydroperoxy derivatives of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) can be separated from their respective phospholipids by reverse-phase high performance liquid chromatography (HPLC). However, ultraviolet absorption due to conjugated diene cannot detect the hydroperoxy group. In this work, an electrochemical (EC) detector was first applied to the analysis of hydroperoxy phospholipids. Both the PC and PE hydroperoxides from rat liver were reduced quantitatively by the glassy carbon electrode at -300 mV vs Ag/AgCl. Since neither the hydroxy derivatives nor unoxidized phospholipids showed any response, it would seem this technique can be used to distinguish phospholipid hydroperoxides from their hydroxy derivatives. Thus, the reverse phase HPLC-EC detection method is proposed for the specific analysis of hydroperoxy phospholipids in biological tissues.