Voltammetric evaluation of chitosan as an effective complexing ligand for the removal of toxic heavy metals

Abstract

Program of the 59th Annual Meeting of the International Society of Electrochemistry, 2008:138: The aim of this study is to evaluate de complexation of toxic heavy metals such as Pb, Zn, Cd and Cu by three commercial chitosans with different molecular weights. For this purpose, the complexation capacity of chitosan was evaluated through competitive deposit of the metals onto the HMDE from ligand-containing solutions and subsequent voltammetric measurement of the anodic stripping signal. Chitosan and spiked metal solutions were dissolved in an acetic-acetate buffer solution (pH=3,5). The complexation capacity was also evaluated at different concentrations of chitosans. Up to now, preliminary results indicate that chitosan complexes more effectively Zn than Pb, probably due to the lower size of Zn which allows its inclusion into the available linking sites of chitosan. Besides, Zn stripping peak shows a marked decrease in its intensity and a displacement towards less negative potentials, proving the high affinity of chitosan for Zn.