Abstract: Triangular-wave current sweeping was used in ACoscillopolarography instead of sine-wave current. The oscillopolarogram obtained is similar to that obtained with sine-wave current. The appearance or disappearance of incision on the oscillopolarogram can be used to indicate the end-point of titration. The relationship of incision height hi to the concentration of depolarizer and current sweeping rate Vare respectively as follows.h_i(mV) = -0.02300 + 4.702×10^-4C₀^*(-2/3) h_i(mV)= -0.02807 +950.68V^(2/3) When Vis very lower 5.0×10^-9mol/L Tl⁺ ion can be determined by this method

Key words: AC Oscillopolarography, Triangular-wave current sweeping