Abstract: In some cases, feeding back a current proportional to dE/dt will make the incision on the higher order differentiation more sensitive. The end-point will be very sharp. Smaller | dC_d/dE | and | d²C_d/dE²| values at the incision potential make the incision sensitivity increase to a greater extent by feeding back a current. Using ion incisions on the higher order differentiations to indicate the end-point of titrations, Cd²⁺, Ni²⁺, Co²⁺, Pb²⁺ and Zn²⁺ can be directly titrated with EDTAor CyDTA, Ni in Al-Ni alloy can be accurately determined by addition of excess EDTAfollowed by back titrations of the excess amount with Zn²⁺.

Key words: Oscillopolarographic titration, Chelometric titration, Al-Ni alloy