Electroanalytical Device for Cadmium Speciation in Waters. Part 2: Automated System Development and Cadmium Semicontinuous Monitoring

A full-automated electroanalytical device is presented here. It is composed of an electrochemically adapted automation module and a competitive screen-printed sensor modified ex situ by a very low quantity of mercury. The contribution of this automated apparatus to analyses is described in detail. Coupled with an UV-photolysis unit, it has permitted the rapid detection of both total and electrochemically accessible cadmium in solutions containing 10mg L-1 of humic substances without addition of reagents. Semicontinuous monitoring of tap water doped with 5.3 mu g L-1 of cadmium, in presence of traces of lead and copper, has been successfully achieved for 7 days.