Suitability of Stripping Chronopotentiometry for Heavy Metal Speciation Using Hydrogen Peroxide as Oxidant: Application to the Cd(II)-EDTA-PMA System

Abstract

The possibilities of stripping chronopotentiometry (SCP) for heavy metal speciation have been tested in the modality of chemical oxidation using the model systems Cd(II)-polyacrylic acid (PMA), Cd(II)-EDTA and Cd(II)-PMA-EDTA. The use of 0.03% H 2 O 2 as a chemical oxidant provides reliable results from transition times, but peak potentials are dramatically affected by the presence of this reagent. The study suggests that chemical-oxidation SCP can be a technique complementary to other stripping modalities in the study of inert and macromolecular labile metal complexes.

Stripping Chronopotentiometry in Environmental Analysis

“…They also pointed out the dramatic increase of the interference of dissolved oxygen as the applied current decreases. Some of these considerations were experimentally tested by Serrano et al in mercury film electrodes, which proved to be a good choice to ensure total depletion regime in a wide range of stripping currents [76,77] and using H 2 O 2 as chemical oxidant [78]. Additionally, they successfully applied the adsorptive and cathodic CCSCP modality to metal complexes of thiol-rich peptides, whose electrochemically inert and irreversible nature make them silent in the anodic constant current mode [79,80].…”