Metallspeziierung in Bodenlösungen mittels Dialysen- und Ionenaustauscherverfahren

Metal speciation in soil solution by dialysis-and ion exchange resin procedures A graduated separation procedure was applied for determining ionic and organic species of main and transition elements in soil solutions. Dialysis of the samples against pure water was found to be an appropriate method for analyzing weak complexes. Ionic forms could be differentiated from soluble strong organic complexes by varying electrolyte concentrations and cation exchange resin. The results of experiments which cation exchange resin in direct contact with the sample (column-mode and batch- mode) were compared with those from dialysis. Thus, three types of element forms could be distinguished: such forms, which could be characterized as inorganically bound ones (K, Na), such elements, which were only weakly bound to organic compounds in order to maintain electrical neutrality (Ca, Mg, Mn, Zn, Cd) and such elements, which were strongly complexed by organic molecules to a high extent (Cu, Cr, Pb, Fe, Al).