Modification of electrodes with adsorbed polyamino acids. Part 1. Cathodic stripping voltammetric determination of copper(II) at a hanging mercury drop electrode using adsorptive accumulation on an adsorbed layer of poly-L-histidine
Abstract
The application of a hanging mercury drop electrode, modified by adsorption of poly-L-histidine, to the determination of CuII in aqueous solutions has been studied. Selective and rapid pre-concentration of CuII on the poly-L-histidine film was observed, even from dilute and quiescent solutions. Copper(II) was determined by differential-pulse adsorptive stripping voltammetry between 5 × 10–9 and 4 × 10–7M after a 2-min accumulation time, using the reduction peak of its complex, at –0.4 V versus an Ag-AgCl reference electrode, obtained in acetate buffer solution of pH 4.5. No significant interference was observed from 1 × 10–6M levels of ethylenediaminetetraacetic acid, chromium(III), lead(II), nickel(II), cadmium(II) and manganese(II).