NEW SENSITIVE ASSAY FOR MEASUREMENT OF HYDROPEROXIDES

The enzyme glutathione (GSH) peroxidase [EC 1.11.1.9] can be used to measure hydroperoxides quantitatively, easily and specifically. A timed reaction of GSH peroxidase, coupled with the oxidation of NADPH by GSH reductase, allows a direct spectrophotometric measurement of hydroperoxide. Addition of catalase prior to the addition of GSH peroxidase permits the distinction between H2O2 and organic hydroperoxides. The solvents that can be used with the assay include methanol, ethanol, water and aqueous solutions of detergents, e.g., Brij 35, Triton X-100 and cetyl trimethyl ammonium bromide. The utility of the method is demonstrated by the measurement of H2O2 and organic hydroperoxides formed upon ozonolysis of an unsaturated fatty acid.