Cyclopentanone Thiosemicarbazone, a New Complexing Agent for Copper Determination in Biological Samples by Adsorptive Stripping Voltammetry

A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with cyclopentanone thiosemicarbazone (CPTSC) is presented. The method is based on the adsorptive accumulation of the resulting copper-CPTSC complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurements at the reduction current of the adsorbed complex at -0.37 V vs. Ag/AgCl. The optimal conditions for the stripping analysis of copper include pH 9.3, deposition time of 120 s, and a deposition potential of -0.1 V (vs. Ag/AgCl). The peak current is linearly proportional to the copper concentration over a range 3.14 x 10-9 M to 1.57 x 10-6 M with a limit of detection of 1.57 x 10-9 M. The technique has been applied to the determination of copper in biological samples, like urine and whole blood.