Abstract: Anew electrochemistry method, phase-selective a.c.oscillovoltammetry, was developed in this paper.With the aid of the home-built instrument constructed by operational amplifiers, a reverse ladder-shape voltage was superposed onto the original dE/dt-t curve, therefore an oscillovoltammogram“i_f-E”was obtained, By selecting a suitable phase-angle between the ladder-shape voltage and the dE/dt-t curve, the incision on“dE/dt-E”oscillogram can be converted into a sharp peak on“i_f-E”curve.Experimental results showed that the peak height is a function of depolarizer concentration over a limited range of concentrations.The detection limit is 10^-6 mol/L, which is much better than that of“dE/dt-E”.

Key words: A.C.Oscillochronopotentiometry, Phase-selective oscillovoltammetry, Incision