Anodic stripping voltammetric determination of mercury in water by using a new electrochemical flow through cell

Abstract

A flow through electrochemical cell was designed for the implementation of a simple, efficient, rapid and sensitive method for determination of mercury in water samples by anodic stripping voltammetry. A solid gold or a gold film electrode can be used as working electrode in a wall-jet configuration of the cell. The analyte is electrolyzed on the electrode surface by pumping the liquid sample through a continuous flow manifold at a flow rate of 8 mL/min. Deposition efficiency increased by increasing the velocity at which the sample arrives to the cell. After deposition of the analyte, it was stripped from the electrode by using a linear anodic potential scan at 35 mV/s. Geometric and hydrodynamic variables of the system were studied in order to optimize the analytical response. A detection limit of 0.05 ng/mL was reached by using a preconcentration time of 540 s. The repeatability expressed as relative standard deviation was always less than 3%. The method shows a good selectively and was successfully applied to the determination of mercury in different water samples.