Determination of copper by adsorptive stripping voltammetry of its complex with adenine

Abstract

An electrochemical adsorptive stripping approach is presented for the trace measurement of copper. The method is based on the reduction of Cu(II) at pH 4.3 adenine (Ade) containing solution at - 90 mV (vs. SCE), adsorption of Cu-Ade complex on hanging mercury drop electrode (HMDE) and the voltammetric determination by further reduction to Cu(0) at HMDE. Experimental optimum conditions were determined in the fundamental studies. The results show that the best base solution consists of 0.05 mol L-1 acetate buffer solution (pH 4.3) and 8 × 10-6 mol L-1 adenine. For an accumulation period of 120 s, the linear range and the detection limit were found as 1.5 × 10-9 -4.5 × 10-8 mol L-1 and 5 × 10-10 mol L-1, respectively. The relative standard deviation (RSD) for determination of 1 × 10-8 mol L-1 was 5% (n = 5). The method has been applied to the analysis of copper in analytical reagent grade salts and also in cow's liver tissue with satisfactory results.