Influence of organic solvents on the separation selectivity in capillary electrophoresis

A review is presented dealing with the investigation of the effect of organic solvents, either pure, mixed with other organic co-solvents, or as aqueous-organic mixtures used as separation medium for capillary electrophoresis (CE). The review deals with those capillary electrophoretic techniques that are based on the different effective mobilities of the separands, namely capillary zone electrophoresis (CZE) and capillary isotachophoresis (ITP) (displacement electrophoresis). Methods like micellar electrokinetic chromatography (MEKC), or CZE with inclusion complexes, that apply organic solvents for adjusting hydrophobic interactions, are not included. This review focuses on the discussion of fundamental physico-chemical aspects of the effects of organic solvents on the separation potential of CE and emphasizes the application of organic solvents on the separation selectivity for the following classes of compounds: inorganic ions, small organic ions, pharmaceuticals, amino acids, peptides and proteins. (C) 1997 Elsevier Science B.V.