Cells for electroanalytical studies

Potential control or potential measurements are fundamental to electroanalytical studies, so the cells used are usually of the three-electrode type. A typical cell for electroanalytical work, such as linear sweep and cyclic voltammetry, is shown in Fig. 6.2. 

The cell consists typically of a 10-20 mL vessel and an electrode holder made of plastic or Teflon with holes for the working (W), reference (R) and counter (C) electrodes. In addition, there is an inlet for an inert gas, usually nitrogen or argon, by which the solution is purged before the measurements are made. Usually also, a gentle stream of the inert gas is maintained over the surface of the solution during the electroanalytical measurements. 

There are two reasons for this precaution. First, molecular oxygen is easily reduced (to the superoxide ion), which may interfere with studies of other reduction processes second, the radical ions or and/or radicals formed as a result of the electrode process may react with oxygen. 

---

Fig. 6.2 Schematic of a typical cell for electroanalytical studies. (W) Working electrode (R) reference electrode (C) counter electrode. An inlet for an inert gas is also shown.

---