In order to investigate the amount of vinyl chloride in air, the hydrogenation of vinyl chloride to ethyl chloride is used. This method of determination is preferable to the other methods described in the literature because: (a) it proves that only vinyl chloride goes through hydrogenation by its displacement to the ethyl chloride peak in the chromatogram; (b) the actual amount of vinyl chloride can be obtained in the case of superimposed or interfering peaks (e.g., various gases contained in air samples), either by calculating the ethyl chloride peak area or by the reduction of the peak area in the region of the same retention time as the vinyl chloride peak in the related chromatogram. In this study various kinds of catalysts for hydrogenation purposes at temperatures ranging from -20 to 250 degrees have been used. Among the catalysts used palladium gives the best results at low temperature.