ENHANCEMENT OF SELECTIVITY IN CAPILLARY ELECTROPHORETIC SEPARATIONS OF METALS AND LIGANDS THROUGH COMPLEX-FORMATION

A significant improvement of separation selectivity can be achieved in capillary electrophoresis by exploiting the formation of complexes wh ich modify the analyte electrophoretic mobilities. Many organic compou nds with electron-donor properties can form weak charge transfer compl exes with suitable metals. These types of complexing equilibria can be exploited in the separation of both species involved in complex forma tion: metals and organic compounds. The first part of this article wil l review the use of complexation reactions to enhance separation selec tivity in the analysis of metals whereas the second part will consider addition of metal ions to the background electrolyte to achieve separ ation of organic ligands. (C) 1998 Elsevier Science B.V.