The Silver Amalgam Film Electrode in Adsorptive Stripping Voltammetric Determination of Palladium(II) as Its Dimethyldioxime Complex

The paper features a description of a sensitive adsorptive stripping voltammetric protocol for the palladium(II) determination in the presence of dimethylglyoxime (DMG) at an amalgam film electrode (Hg(Ag)FE) of prolonged analytical applicability. The procedure is based on the adsorptive preconcentration of the Pd(II)-dimethylglyoxime complex onto the (Hg(Ag)FE) at -0.45 V, followed by a negatively going square-wave voltammetric scan. Factors affecting the stripping performance, such as the composition of the supporting electrolyte, including different ligands, DMG concentration, pH, potential and time of preconcentration, and SW frequency have been investigated and optimized. The optimized procedure yields favorable and highly stable stripping responses with good precision (RSD = 3% for a Pd concentration of 2 mu g/L), low detection limit (0.15 mu g/L Pd(II)), and good linearity (from 1.0 mu g/L up to 50 mu g/L, R-2 = 0.998) with a deposition time of 60 s. Possible interferences from coexisting ions and surface active substances were studied.