Evaluation of ionic imprinted polymers by electrochemical recognition of rare earth ions

Novel ionic imprinted polymers were prepared using covalent combination of polyamine ligands and bentonite. Cyclic voltammetry was applied to electrochemically recognise rare earth ions using carbon paste electrodes modified with these ionic imprinted polymers. Two well-defined redox peaks, representing the adsorptive complexes of the rare earth ions and tribromoarsenazo, were found using scanning potentials from -0.80 to 0.00 V vs. SCE. These peaks were used to determine the rare earth ions. Keeping the rare earth ion concentrations constant permitted developing a simple, effective method to evaluate quantitatively the ionic recognition of the imprinted polymers. The rare earth ion adsorption process on the surface of ionic imprinted polymers was found to be diffusion-controlled. The peak current in the cyclic voltammograms enabled calculation of the recognition ratios of ionic imprinted polymers. (C) 2007 Elsevier B.V. All rights reserved.