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.