Capillary Electrophoresis/ Electrochemistry

proving to be a powerful separation technique. Electrochemical (EC) methods offer significant advantages over classical spectroscopic techniques for CE separations because electrochemistry occurs directly at an electrode surface and, thus, the limits of detection are not compromised by the small dimensions inherent in CE. This is in contrast to spectrophotometric detectors, in which the signal is pathlength-dependent and therefore influenced by the i.d. of the separation capillary. Moreover, electrochemical detectors do not require an optical carrier, and as a result, are much less costly than absorption and fluorescence detectors. This is especially significant when one considers that electrochemical detectors are easily tunable without such components as monochrometers and filters. While laser-induced fluorescence detection offers comparable sensitivity, it is restricted by the limited number of wavelengths of commercially available lasers. In addition, derivatization (either preor postcolumn) is often required, which further limits its usefulness.