DERIVATIZATION IN CAPILLARY ELECTROPHORESIS

In recent years capillary electrophoresis (CE) has been developed into a versatile separation technique, next to gas and liquid chromatograp hy (LC), well suited for the determination of a wide variety of e.g., pharmaceutical, biomedical and environmental samples. The main advanta ges of CE over chromatographic separation techniques are its simplicit y and efficiency. It is well recognized, however, that the sensitivity and selectivity of the detection are relatively weak points of CE. On e way to overcome these limitations is the conversion (derivatization) of the analytes into product(s) with more favourable detection charac teristics. Although, in principle, almost any detection mode can be co mbined with a derivatization procedure, in practice, fluorescence moni toring is favoured in most cases. This paper aims to give a short over view on the various reagents that can be used for pre-, post-and on-co lumn derivatization in CE. First, a short introduction is given on CE as an analytical technique, followed by a discussion of the pros and c ons of the various modes of derivatization, a comparison of derivatiza tions in CE with derivatizations in LC, the principles of fluorescence and prerequisites for a good fluorophore and the potential of using d iode lasers in combination with a labelling procedure. With respect to the derivatization reagents the emphasis is on the labelling of amino , aldehyde, keto, carboxyl, hydroxyl and sulfhydryl groups. (C) 1998 P ublished by Elsevier Science B.V.