Derivatization trends in capillary electrophoresis

This survey gives an overview of recent derivatization protocols, starting from 1996, in combination with capillary electrophoresis (CE). Derivatizati on is mainly used for enhancing the detection sensitivity of CE, especially in combination with laser-induced fluorescence. Derivatization procedures are classified in tables in pre-, on- and postcapillary arrangements and, m ore specifically, arranged into functional groups being derivatized. The am ine and reducing ends of saccharides are reported most frequently, but exam ples are also given for derivatization of thiols, hydroxyl, carboxylic, and carbonyl groups, and inorganic ions. Other reasons for derivatization conc ern indirect chiral separations, enhancing electrospray characteristics, or incorporation of a suitable charge into the analytes. Special attention is paid to the increasing field of research using on-line precapillary deriva tization with CE and microdialysis for in vivo monitoring of neurotransmitt er concentrations. The on-capillary derivatization can be divided in severa l approaches, such as the at-inlet, zone-passing and throughout method. The postcapillary mode is represented by gap designs, and membrane reactors, b ut especially the combination of separation, derivatization and detection o n a chip is a new emerging field of research. This review, which can be see n as a sequel to our earlier reported review covering the years 1991-1995, gives an impression of current derivatization applications and highlights n ew developments in this field.