COMPLEXATION CAPACITY OF AQUATIC SYSTEMS IN DEPENDENCE ON DIFFERENT LIGANDS AND HEAVY-METALS - ELECTROANALYTICAL INVESTIGATIONS AND STATISTICAL EVALUATION

Heavy metals exist in natural waters in different species. Mobility an d bioavailability of bound metals can be influenced by some complex fa ctors in the aquatic environment. Therefore, it is useful to determine the complexation properties of various ligands influenced by differen t metals. The copper and zinc complexation capacity was determined for a natural ligand (fulvic acid) and anthropogenic pollutants (e.g. nit rilotriacetic acid and ethylenediaminetetraacetic acid). The interacti ons between several ligands and metal ions and their effects on the co mplexation capacity were analyzed in particular. Applying methods of e xperimental design, such as multifactorial plans, it is possible to de termine influence and interaction of various parameters (e.g. concentr ation of zinc or copper) by a minimum number of experiments. Different ial pulse polarography was used for the determination of the complexat ion capacity. Methods of parametric and robust multiple linear regress ions were applied for the interpretation of the measured values.