On the adsorption voltammetry of indium(III) in the presence of oxine

Abstract The adsorptive voltammetric behaviour of the indium(III) complex with oxine at a hanging mercury drop electrode has been investigated in HAc+NH 4 Ac buffer (pH 4.0). On the basis of the adsorptivity of the indium(III) complex at the electrode, sensitive adsorption voltammetry was developed. The procedure was different from the usual linear sweep adsorption voltammetry. First, the indium(III) complex was reduced to indium amalgam at a more negative potential. Then the potential was adjusted to a more positive value, at which indium(0) was oxidized to indium(III) complex again and adsorbed on the surface of the electrode. The peak current of the reduction of the indium(III) complex accumulated adsorptively was directly proportional to the indium(III) concentration in the bulk solution over the range 3 × 10 −10 −7 × 10 −8 mol/1. The detection limit was 1.5 × 10 −10 mol/1.