Determination of the yield of radiation-induced peroxidation of sodium linoleate in aqueous monomeric and micellar solutions.
Peroxidation of polyunsaturated fatty acids such as linoleic acid in aqueous micellar solution proceeds through a free-radical chain mechanism and is accompanied by the formation of conjugated dienes, some in the form of hydroperoxides. In the course of an investigation of radiation-induced oxidation of aqueous sodium linoleate, we have measured three indexes of peroxidation-conjugated dienes, hydroperoxides and thiobarbituric acid-reactive substances-by means of absorption spectroscopy, high-pressure liquid chromatography and spectrofluorimetry, respectively. There are linear correlations between the amounts of conjugated dienes, hydroperoxides and thiobarbituric acid-reactive substances. The radiolytic yields have been determined from the radiation dose dependence of the three markers of peroxidation as a function of sodium linoleate concentration. The results obtained indicate a strong effect of the concentrations of oxygen and linoleate on the yields of the products. The yields at different lipid concentrations display a large increase in chain propagation length; this is discussed in terms of the effect of micellar size.
Hauville
C
C
Laboratoire de Chimie-Physique, URA 400 CNRS, Université Paris V, France.
Rémita
S
S
Thérond
P
P
Rouscilles
A
A
Couturier
M
M
Jore
D
D
Gardès-Albert
M
M
D002851:Chromatography, High Pressure Liquid; D004307:Dose-Response Relationship, Radiation; D019787:Linoleic Acid / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000528:radiation effects*; D008823:Micelles; D012996:Solutions; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D008823:Micelles; D012996:Solutions; D017392:Thiobarbituric Acid Reactive Substances; D019787:Linoleic Acid