Polarographic catalytic hydrogen currents were studied in ammonium chloride ammonium hydroxide buffered solutions of various thio compounds in the presence of chromium (VI) ion. It was found that the catalytic activities of structurally similar thio compounds decrease in the following order. pentamethylene dithiocarbamate > diethyl dithiocarbamate > ammonium pyrrolidine dithiocarbamate > potassium ethyl xanthate
