Determination of Zinc in Seawater by Anodic Stripping Voltammetry

A sensitive method for detection of electrolabile zinc in seawater is presented. A detection limit in the range down to low nM seems possible in seawater using differential pulse anodic stripping voltammetry with a rotating dental amalgam electrode and a plating time of 600 seconds. Well-defined peaks for zinc were observed in seawater samples without the need for any reagent addition. Linear response was found for different low concentration ranges of zinc in real costal seawater samples. The technique was also used for quantifying zinc concentrations in real estuarine water samples from the river Mersey, Liverpool. The optimization included the use of an activated rotating dental amalgam disk electrode, by applying a negative potential of – 5V for 10 seconds while the electrode was rotated. Also interferences were tested; measurements in the presence of EDTA or sideophores indicated the possibility of using this method for study zinc speciation. The presented results confirm indicates that the procedure can be useful detection of zinc in costal seawater and interesting also for surface seawater.