Electroanalytical devices electrochemical sensors

All analysts are familiar with the principles of potentiometry and potarography and indeed, most analytical laboratories will contain a pH meter and a polarograph. However, electrochemical methods arc, in general, not very important in modern analysis. In contrast, there arc spccifiG applications such as trace metal ion analysis in water and effluents and also some other aspects of environmental analysis for which electrochemical methods are particularly attractive. This is because (1) some methods, especially anodic stripping voltammetry, have a very high sensitivity for heavy-metal ions and the lowest detection limit of from 10 to mol dm is well below that of other available methods (2) electrochemical methods are well suited for modification to on-line and/or portable devices for analysis in the held. Whether the analysis is based on current, conductivity or the response of an ion-selective electrode, both the cell and the control electronics are readily miniaturized and operate on low power Hence, this chapter considers the principles of the electroanalytical methods important in environmental and on-line analysis, together with biochemical applications of electrochemical sensors. 

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