Determination of Copper by Adsorptive Stripping Voltammetry in the Presence of Calcein Blue

Abstract

Abstract An electrochemical adsorptive stripping approach is presented for the trace measurement of copper in some real samples. The method is based on the reduction of Cu 2+ at pH 5.5 calcein blue (CB) containing solution at −250 mV (vs. Ag/AgCl), adsorption of CuCB complex on hanging mercury drop electrode (HMDE) and the voltammetric determination by further reduction to Cu + at HMDE. Experimental optimum conditions were determined in the fundamental studies. At the experimental optimum conditions the adsorbed complex of Cu 2+ and calcein blue gives a well defined cathodic stripping peak current at −0.135 V, which has been used for the determination of copper in the concentration range of 0.02 to 15 ng/mL with accumulation time of 90 s. The relative standard deviation ( RSD ) for the determination of 0.5 and 6.0 ng mL −1 were 2.60 and 1.94% respectively. ( n =10). The method has been applied to the analysis of copper in analytical reagent grade salts and tap water, mineral water and drug samples with satisfactory results.