Differential pulse adsorptive stripping voltammetric determination of nickel and cobalt in high purity aluminium

A sensitive method for the simultaneous determination of trace amounts of nickel and cobalt in pure aluminium has been described using differential pulse adsorptive stripping voltammetry (DPASV) by adsorptive accumulation of the dimethyl glyoxime (DMG) complex on the hanging mercury drop electrode (HMDE). As supporting electrolyte 0.1 mol/l ammonia buffer, pH 9.0, containing ammonium citrate and 5×10^–4 mol/l DMG has been used. The determination limit obtained has been as low as 0.5 g/g for Ni and 0.2 g/g for Co (using about 100 mg sample) with a relative standard deviation of 13% and 22%, respectively.