Liquid-liquid extraction procedures for sample enrichment in capillary zone electrophoresis

This review article presents an overview of applications of liquid-liquid e xtraction (LLE) for analyte enrichment and clean-up of samples prior to cap illary zone electrophoresis (CZE). The basic principles of LLE are discusse d with special emphasis on analyte enrichment. In addition, attention is fo cused on the requirements for the final extract to be compatible with CZE. The paper discusses selected examples from the literature with special emph asis on detection limits in drug analysis and in environmental chemistry. F inally, the paper focus on alternative liquid-phase extraction concepts bas ed on electroextraction, supported liquid membranes, and liquid-phase micro extraction. (C) 2000 Elsevier Science B.V. All rights reserved.