Organically bound cadmium with reference to its speciation and bioavailability

Abstract

The study of the electrophoretic nature and quantification of organically bound cadmium was carried out using the radiotracer ^115mCd by electrophoresis and ion exchange chromatography on Dowex-50, Dowex-1 and XAD-2 resins. The electrophoretic assay indicated the existence of organically bound cadmium in cationic, anionic and neutral forms. Column experiments were found to be more suitable and accurate for the quantitative estimation compared to batch experiments. The existence and characterization of organically bound cadmium, supported the observation in the metal-organic acid interaction in soil-plant system that the tendency of metals to interact with organic ligand led to metal solubilization, resulting into increased mobilization and, therefore, adds an important dimension to the mechanistic aspects of plant enrichment of the metals.