Determination of lipid hydroperoxides in low density lipoprotein from human plasma using high performance liquid chromatography with chemiluminescence detection

A high performance liquid chromatographic system with chemiluminescence detection (HPLC‐CL) was used for determining phospholipid hydroperoxides in human plasma low density lipoprotein (LDL). This system involved separation of phospholipids from LDL‐total lipids with normal phase silica gel HPLC and post‐column detection of hydroperoxide‐dependent chemiluminescence produced by luminol oxidation during the reaction of hydroperoxide with cytochrome c‐haeme. By using HPLC‐CL, we could detect phosphatidylcholine hydroperoxide (PCOOH) in human plasma LDL, and the LDL‐PCOOH concentration was significantly higher in patients with atherosclerosis and hyperlipidemia than that of healthy volunteers. The LDL‐PCOOH level was proportional to the plasma total cholesterol concentration.