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.