Novel renovated silver ring electrode for anodic stripping analysis of Pb(II) and Cd(II) traces in water samples without removal of oxygen and surfactants

This work describes a novel type of renovated silver ring electrode (RSRE), as mercury-free sensor, for anodic stripping voltammetry (ASV). The great advantages of the RSRE are simplicity, periodic renovation of the surface and the possibility of repetitive measurements on the surface completely free from reaction products, adsorbed surface-active species, etc. The sensor was tested for the detection of nanomolar concentrations of Pb2+ and Cd2+ by ASV in water samples without removal of oxygen and surfactants. Detection limits of 0.5 nM for Pb2+ and 2 nM for Cd2+ have been achieved following 60 s electrodeposition. The validation of the proposed RSRE was made by Pb2+ and Cd2+ determination using the certified reference materials (Surface Waters). The RSRE was successfully applied to Pb2+ and Cd2+ analysis in tap water and to river water with a high content of organic contaminants. (c) 2009 Elsevier B.V. All rights reserved.