A typical electrochemical cell consists of the sample dissolved in a solvent, an ionic electrolyte, and
three (or sometimes two) electrodes. Cells (that is, sample holders) come in a variety of sizes, shapes,
and materials. The type used depends on the amount and type of sample, the technique, and the analytical
data to be obtained. The material of the cell (glass, Teflon, polyethylene) is selected to minimize
reaction with the sample. In most cases the reference electrode should be as close as possible to the
working electrode; in some cases, to avoid contamination, it may be necessary to place the reference
electrode in a separate compartment. The unique requirements for each of the voltammetric techniques
are described under the individual techniques.