Voltammetric behaviour of marine hydrophobic copper complexes: effect of adsorption processes at a mercury electrode

The voltammetric behaviour of copper in the presence of marine hydrophobic organic matter and soil fulvic acid was examined by differential-pulse anodic stripping voltammetry (DPASV) in sodium perchlorate. These organic substances strongly adsorb on a mercury electrode, thereby affecting the peak current. The extent of this interference is related to the charge on the electrode during the plating step, but the mechanism of the influence on the anodic peak is mainly connected with the stripping step. A cathodic potential step whereby the effects of adsorption can be removed is described. This modified DPASV method was used to evaluate the lability of copper-organic complexes and to elucidate the effects on the anodic current due to the adsorption process.