A SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF HYDROPEROXIDES IN LIPOSOMES

A modification of the Asakawa-Matsushita iodometric assay method for t he determination of the content of lipid hydroperoxides was developed which permits the simultaneous processing of many samples of high lipi d content. The method has the advantages of simplicity as well as good reproducibility, so it is not necessary to process standards with eac h determination. Our technique exceeds the sensitivity attained with o ther spectrophotometric determinations reported in the literature. The method requires the total elimination of water from the samples, and this was accomplished using an azeotropic mixture of ethanol:water of 96:4. The results obtained with liposomes indicate that the method is applicable to biological material limited to small volume samples, ran ging 5-50 mu l. We want to emphasize that this method permits the stud y of the peroxidation process as function of time. (C) 1998 Elsevier S cience B.V. All rights reserved.