Synergetic adsorption of the copper-phenanthroline-tributylphosphate complex at a mercury drop electrode

In the framework of electrochemical investigations on the synergetic adsorption of mixed ligand complexes at the mercury drop electrode, a cathodic stripping voltammetric method for the determination of copper(II) as mixed ligand complex with 1,10-phenanthroline (Phen) and tributylphosphate (TBP) in aqueous solutions was examined. The measurements were based on the accumulation of the copper-phenanthroline complex on the mercury drop surface covered with a layer of TBP molecules. The copper reduction response is strongly enhanced due to the formation of a mixed complex which is very hydrophobic and, therefore, strongly adsorbs at the electrode surface. The effect of various parameters (pH, metal and ligand concentrations, time and potential of accumulation) on the reduction process is examined. The voltammetric procedure was then applied to the detection of copper in natural water samples.