Voltammetric Methods of Analysis
In voltammetry a time-dependent potential is applied to an electrochemical cell, and the current flowing through the cell is measured as a function of that poten- tial. A plot of current as a function of applied potential is called a voltammogram and is the electrochemical equivalent of a spectrum in spectroscopy, provid- ing quantitative and qualitative information about the species involved in the oxidation or reduction reaction.15 The earliest voltammetric technique to be introduced was polarography, which was developed by Jaroslav Heyrovsky (1890–1967) in the early 1920s, for which he was awarded the Nobel Prize in chemistry in 1959. Since then, many different forms of voltammetry have been developed, a few of which are noted in Figure 11.1. Before examining these techniques and their applications in more detail, however, we must first consider the basic experimental design for making voltammetric measure- ments and the factors influencing the shape of the resulting voltammogram.