Stripping Voltammetric Measurement of Trace Metal Ions at Screen-printed Carbon and Carbon Paste Electrodes

Abstract

Screen-printed carbon electrodes (SPCEs) and carbon paste electrodes (CPEs) were prepared as "mercury-free" electrochemical sensors for the determination of trace metal ions in aqueous solutions. SPCEs were coated with conducting polymer layers of either polyaniline (PANI), or polyaniline-poly(2,2′–dithiodianiline) (PANI-PDTDA). Furthermore, CPEs containing electroactive compounds with reactivity towards metal ions were employed to obtain enhanced selectivity. Optimised experimental conditions for Hg2+, Pb2+, Ni2+ and Cd2+ determination included the supporting electrolyte concentration, deposition potential (Ed) and accumulation time (tacc). Initial results showed linearity in the examined concentration range between 1 × 10-9M and 1 × 10-6M for laboratory prepared solutions