USE OF CHARGE-TRANSFER INTERACTING ADDITIVES IN ELECTROKINETIC CHROMATOGRAPHY

In this paper, a new approach to introduce alternative selectivities t o electrokinetic chromatography (EEC) using pi-electron rich anions as separation buffer additives is presented. We describe the results obt ained with two dyes, Cardiogreen and a porphyrine-based additive (tetr aphenyl porphyrine tetrasulfonate), for the separation of nitroaromati c and phenolic compounds. Unfortunately, the new additives preclude di rect UV-vis detection with traditional working procedures. A strategy to overcome the detection problem making use of a partial filling of t he capillary and the application of a counterpressure has been develop ed. Achievable efficiencies and selectivity changes es compared with S DS have been investigated. (C) 1997 John Wiley & Sons, Inc.