Abstract: In a redox reaction process, the oxidized state of organic compounds is increased through the steps of directing oxides of nitrogen together with a reducing agent selected from oxygenated compounds and aromatic compounds through a catalyst bed in the form of supported gold heated to a temperature sufficient to reduce the oxides of nitrogen present to nitric oxide, after which the higher oxidized forms of organic compounds are recovered. The organic compounds to be oxidized can be separated by chromatography before introduction with one of the oxides of nitrogen into the catalyst bed, and detection of the reducing agent by chemiluminescent measurement of NO.sub.2.sup.* enables determination of the higher oxidized species produced.