Detection of oxygen consumption during very early stages of lipid peroxidation by ESR nitroxide spin probe method

Oxygen consumption during the very early stages of the spontaneous peroxidation of egg yolk phosphatidylcholine membranes was studied by monitoring the oxygen concentration in the aqueous phase of the sample using a spin-probe closed-chamber method. The method depends on the broadening by oxygen of the proton superhyperfine lines of the electron spin resonance spectra of the nitroxide radical spin probe 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrroline-1-yloxyl. It is concluded that this method is useful in monitoring lipid peroxidation and that it monitors the onset of the peroxidation process before the commonly used thiobarbituric acid assay detects the peroxidation products.