The method described in the paper solves a simple and accurate determination of hydrogen sulfide and mercaptans in gaseous hydrocarbon mixtures. The method is based on absorption of a sample in an antioxidant solution (alkaline solution of ascorbic acid with an admixture of Chelaton III) and subsequent parallel determination of the salts formed by cathodic stripping voltamperometry. A sufficient difference in potentials of both substance types (approx. 200 mV) enables the determination.