ABSTRACT
This chapter presents on the principles of electrochemical detection and discusses amperometric detection (AD). The emphasis will be on the advantages of AD over some of the other widely applied detection techniques (e.g., absorbance, fluorescence), some of its inherent disadvantages, and the prerequisites for combining liquid chromatography (LC) with AD. In addition to the absorbance, fluorescence, and chemiluminescence detection in LC, electrochemical detection—in particular AD—is gaining popularity. Compounds with poor electrochemical (redox) properties can be detected using electrochemical detection after labeling with a suitable compound having better electrochemical properties. Improvement of electrochemical detectability can also be obtained by a number of nonlabeling procedures. Electrochemical conversions to facilitate the absorbance or fluorescence detection of the analyte are described in the literature, and both the on-line prechromatographic as well as the postchromato-graphic mode have been applied. Enzyme reactions can also be used in the postchromatographic mode in order to allow the AD of nonelectroactive compounds.
