Abstract

The voltammetric determination of the copper complexing capacity (CuCC) in aquatic systems for non-buffer conditions is described and applied to 16 pore water samples. On the basis of the potential shift of the copper peak the copper complexes were classified as labile under the present experimental conditions. The CuCC varied from <0.45 to approximately 2.50 micromol per l. For three samples an increase in the lead concentration was observed with increasing copper additions, indicating competitive behaviour of lead and copper for the available binding sites. For each point of the titration curve, the conditional stability (K) of the copper complexes could be estimated on the basis of the CuCC, the total Cu content and the voltammetric Cu concentration. Values for K were found to vary from approximately 4*10 exp. 6 to 1*10 exp. 9 l per mol, depending on the sample and the degree of coverage.