A novel screen-printed electrode modified with lead film for adsorptive stripping voltammetric determination of cobalt and nickel

The paper presents the first report on the preparation of an in situ plated lead film screen-printed electrode (PbF-SPE) and its application for adsorptive stripping voltammetric determination of nickel and cobalt in the form of the complexes with dimethylglyoxime. The lead film was electrochemically deposited in situ on a commercially available three-electrode screen-printed electrochemical strip from a 0.2 M ammonia buffer solution (pH 8.2) containing 4 × 10−5 M Pb(NO3)2 and 1 × 10−5 M dimethylglyoxime. The composition of the supporting electrolyte and the influence of accumulation time on the stability of the lead coating and on the sensitivity and reproducibility of Ni and Co responses are discussed. The repeatability of the Ni(II) and Co(II) adsorptive stripping voltammetric signals obtained at the lead film screen-printed electrode were equal to 4% and 3%, respectively (n = 10). The limits of detection established for simultaneous determination of Ni and Co for 90 s of accumulation time were 0.2 and 0.3 μg L−1, respectively. Voltammetric studies were complemented with optical and scanning microscopic observations.