Three-electrode voltammetric analytical system

Fig. 13.2 Typical three-electrode voltammetric analytical system.

In this section, the effect of chemical reactions coupled with electron transfer processes studied by three pulse methods is discussed, namely in normal pulse (NP), differential pulse (DP), and square-wave polaro-graphic/voltammetric techniques. These methods, especially DPV, belong to the most frequently employed voltammetric methods in contemporary analytical practice. In recent years, criteria for elucidation of electrode mechanisms have been also developed for these techniques. Under favorable conditions (in pure kinetic zone), the electrode mechanisms for simple reaction systems can be established without difficulties. 

The use of CEP-coated microelectrodes offers several advantages over the use of conventionally sized electrodes. The use of microelectrodes means that volt-ammetric measurements can be carried out using much lower concentrations of supporting electrolytes. With the FIA system for detection of ions this enables much lower (sometimes three orders of magnitude lower) detection limits to be obtained [31]. Also, with microelectrodes, faster switching routines can be used without distortion of the voltammetric response [223]. The use of microelectrodes also enables microarrays to be employed [77,224]. This enables multicomponent analyses and pattern recognition to be used for analytical purposes. 

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