COPPER COMPLEXATION BY NATURALLY-OCCURRING ORGANIC-MATTER - A MULTILIGAND MODEL

Extending the fluorescence quenching single-ligand model of Ryan-Weber , a multiligand model that does not require a direct measurement of th e free metal ion concentration is proposed. It is shown that the probl em of inconsistent negative ligand concentrations, commonly predicted by single-ligand models, may be overcome by using multiligand models. Finally, particular results concerning the conditional stability const ants and ligand concentrations for one-, two and three- ligand cases a re presented for soil fulvic acid, both before and after reverse phase HPLC fractionation.