Analytical application of the cobalt(II) catalytic pre-wave in the presence of thiamine in its disulphide form

Abstract

The cobalt catalytic pre-wave in the presence of thiamine in its disulphide form, and in a borate medium, was studied as a function of the thiamine (disulphide form) and cobalt(II) concentrations and of the pH of the solution. The effects of temperature, the addition of neutral salts and the presence of surface-active agents on the pre-wave are described. The effect of thiamine (disulphide form) is shown on the electrocapillary curves. The electrode process involves the formation of complexes between cobalt(II) and thiamine, in its thiolic form, adsorbed on the dropping-mercury electrode, and the electrochemical decomposition of these complexes with liberation of the catalytic ligand. The analytical application of this pre-wave was studied.