An ASIC-based system for stripping voltammetric determination of trace metals

The work presented here is part of an overall voltammetric design system with a silicon based disposable component for the determination of copper, cadmium, lead and zinc. Voltammetric (the measurement of current as a function of potential) methods of analysis are attractive for determinations of trace metals. They offer a combination of simple low cost instrumentation with excellent sensitivity and detection limits, comparable to those obtainable with instruments costing orders of magnitude greater. The system consists of electrodes, an application specific integrated circuit (ASIC) and software control. Screen-printed silver/silver chloride and carbon electrodes are used in the preparation of mercury film electrodes on which anodic stripping voltammetry is performed for the detection of the four heavy metals listed above. Work has also been carried out to investigate calibration problems caused by the formation of intermetallic complexes.