A difficult analytical problem was solved by combined use of several techniques to assay products from the liquid phase oxidation of paraffins. The method provides a quantitative measure for six classes of oxygenated compounds in the C12-C15 carbon number range. The procedure can be modified to handle mixtures outside of this molecular weight range. Samples are first separated into hydrocarbon and oxygenated compound fractions by elution through silica gel. The two fractions are then analyzed by com-