Catalytic Waves of β-Mercapto-Propionic Acid at the Dropping Mercury Electrode

The polarographic behaviour of β-mercapto-propionic acid (MPA) at the dropping mercury electrode, investigated in ammoniacal cobaltous solution evince the occurrence of catalytic hydrogen wave (E_{\(_2^1\)}1·55); the shape and height of which was found to be influenced by the concentration of buffer constituents and by the presence of the surface active substances and salts. The height of the catalytic wave was found to be independent of mercury pressure, although, it varies linearly with the concentration of MPA (1.0 x 10^-4 M -3·0X 10-3 M). Catalytic hydrogen wave can, therefore, be successfully utilised for the quantitative determination of MPA down to 1.0 x I0-4 M. In the presence of cobaltic ion, however, MPA does not yield catalytic wave.