AUTOMATIC-DETERMINATION OF HYDROPEROXIDES OF PHOSPHATIDYLCHOLINE AND PHOSPHATIDYLETHANOLAMINE IN HUMAN PLASMA

An automatic method for the determination of hydroperoxides of phospha tidylcholine (PC) and phosphatidylethanolamine (PE) is reported. Sampl e plasma was deproteinized with a fourfold volume of methanol. After c entrifugation, the supernatant was injected directly into an HPLC syst em without further treatment. The hydroperoxides of PC and PE were con centrated and washed on an ODS column followed by introduction into tw o analytical columns, a silica gel and an aminopropylsilica gel column , which were connected in series, by column switching. After the separ ation, they were detected by postcolumn detection with diphenyl-1-pyre nylphosphine. The compounds were determined at picomole levels within 30 min with good reproducibilities. By using only a silica gel column as an analytical column, PC hydroperoxides were determined within 20 m in, and samples could be injected into it at 15-min intervals. Those m ethods made it possible to inject a sample of up to 2 ml at one time a nd up to 8 ml by repeated injections and to determine phospholipid hyd roperoxides in human plasma at picomole levels.