Free Eu(III) Determination by Donnan Membrane Technique with Electrochemical Detection: Implementation and Evaluation

Abstract The aim of this study was to develop an analytical method determine free concentrations Europium (Eu(III)) in natural waters. Europium(III) solution detected using cathodic stripping voltammetry after complexation with N -nitroso- -phenylhydroxylamine (cupferron). Optimization parameters allowed us detect nanomolar levels Eu(III) solution. Free measured the Donnan membrane technique which a (the “donor”, containing various ligands) is separated from ligand-free “acceptor”) by cation-exchange membrane. This allows only non-colloidal cationic species pass through it, and adequate time equilibrium reached between both compartments. Total concentration can then be quantified acceptor related sample. Due its high valency, tends adsorb strongly In order physicochemical conditions minimizing adsorption, we analyzed solutions different Ca(II) (as background ion) concentrations. Results showed that 100 mM were necessary make adsorption onto negligible. optimized setup used quantify Eu(III)-dissolved organic matter