HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF PLASMA MALONDIALDEHYDE LEVEL WITHOUT A SOLVENT-EXTRACTION PROCEDURE

A highly sensitive and simple HPLC method for measuring malondialdehyd e (MA) in plasma was developed. For sample preparation, an aliquot of plasma (10 mu l) was mixed with 2.0% thiobarbituric acid (TBA) in 2 M sodium acetate buffer (containing 1 mM DTPA and 0.05% BHT), pH 3.5. Af ter incubating at 95 degrees C for 45 min, the reaction solution was p assed through a 0.2-mu m membrane filter. An aliquot of 10 mu l filtra te was Injected into HPLC system without any extraction procedures. Th e thiobarbituric acid-malondialdehyde (TBA-MA) complex was separated o n reversed-phase HPLC and quantitated with a fluorescence detector. Th e mobile phase was mixture of acetonitrile:water (7:3, v/v) under isoc ratic conditions at ambient temperature, and a single analysis was com pleted in ca. 2.5 min. The minimum detection level for MA was 0.01 pmo l. A very close correlation was observed between this method and the Y agi method, which is widely used for clinical diagnosis. The simple an d inert mobile phase along with a very simple sample preparation makes this method applicable to numerous clinical samples without any diffi culties. (C) 1995 Academic Press, Inc.