Determination of trace amounts of copper(II) by adsorptive stripping voltammetry of its complex with pyrogallol red Original Research Article

A sensitive and selective procedure is presented for the voltammetric determination of copper. The procedure involves an adsorptive accumulation of copper pyrogallol red on a hanging mercury drop electrode, followed by a stripping voltammetric measurement of reduction current of adsorbed complex at −0.2 V (vs. Ag/AgCl). The optimum conditions for the analysis of copper include pH (3.0–4.5), 20 μM pyrogallol red and an accumulation potential of −0.1 V (vs. Ag/AgCl). The peak current is proportional to the concentration of copper over the range 0.4–60 ng ml−1 with a detection limit of 0.07 ng ml−1 with an accumulation time of 60 s. The method was applied to the determination of copper in some analytical grade salts and also in cowʹs liver tissue.