Amplitude Controlled-Potential Techniques

William R. Heineman University of Cincinnati, Cincinnati, Ohio 

Peter T. Kissinger Purdue University and Bioanalytical Systems, Inc., West Lafayette, Indiana 

Classification of Dynamic Techniques via Large-and Small-Amplitude Excitations 

The electroanalytical techniques chronoamperometry, chronocoulometry, and chronoabsorptometry are all based on the same excitation function of one or more potential steps that are applied to an electrode immersed in a nonstirred solution. The system response is thus identical for all three techniques. They differ only in the data domain of the monitored response. Consequently, the common excitation aspect is dealt with here, whereas each monitored response is considered individually in subsequent sections. 

The duration of the potential step (the time interval i of Es) is usually determined by the type of information that the experimenter desires of the particular system. The time may vary from as little as 10 /is to as long as several seconds. The minimum time is limited by the ability of the potentiostat to charge the electrode, whereas the maximum time is determined by the onset of convection from vibrations or density gradients. Special shielded electrodes enable times on the order of 100 s to be reached with no apparent disturbance of the diffiisional process. 

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Heineman, W. P. Kissinger, P. T., Large-Amplitude Controlled-Potential Techniques, in Laboratory Techniques in Electroanalytical Chemistry, Kissinger, P. T. Heineman, W. R., eds., Marcel Dekker, New York, 1984, pp. 51-127. 

Refs. [i] Kissinger PT, Ridgway TH (1996) Small-amplitude controlled-potential techniques. In Kissinger PT, Heineman WR (eds) Laboratory techniques in electroanalytical chemistry, 2nd edn., Marcel Dekker, New York, pp 141 [ii] Smith DE (1966) AC polarography and related techniques theory and practice. In Bard AJ (ed) Electroanalytical chemistry, vol. 1. Chap. 1 Marcel Dekker, New York... 

Kissinger PT, Ridgway TH (1996) Small-amplitude controlled-potential techniques. In Kissinger PT, Heineman WR (eds) Laboratory techniques in elec-troanalytical chemistry, 2nd edn. Dekker, New York... 

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