Conductimetric analysis of the interaction of Cn(II) ions and a humic-likenatural polyelectrolyte (Laurel, Laurus nobilis) mixture

The influence of the ligand and metal ion concentrations on the conductimet ric behavior of humic-like laurel extract-Cu(II) mixtures are analyzed by c onductimetric titrations. The results obtained show that the extracts can b e considered as polyelectrolytic molecules in the presence of heavy cations , forming complexes whose stability (related to the slope of a conductimetr ic excess function versus added Cu(II) plots) is low when compared to stron ger ligands such as humic acids. The influence of ligand concentration and degree of neutralization is discussed. (C) 1999 Elsevier Science B.V. All r ights reserved.