NICKEL AND COBALT DETERMINATION BY CONSTANT-CURRENT POTENTIOMETRY .1.METHOD DEVELOPMENT

Constant current potentiometry was used for nickel and cobalt determin ation in water. All parameters like deposition potential and time, buf fer and DMG concentration, and current density which have an influence on the determination sensitivity were optimized (deposition potential : -0.5 V vs. Ag/AgCl (sat KCl); buffer concentration 0.01 mol/l, pH 9. 3; DMG concentration 0.05 mmol/l and deposition time 10 s, current: -1 5 muA). No significant differences of the determination sensitivity be tween cathodic stripping voltammetry and constant current potentiometr y were found. The latter method is advantageous for automatization.