LARGE-VOLUME STACKING FOR QUANTITATIVE-ANALYSIS OF ANIONS IN CAPILLARY ELECTROPHORESIS .2. LARGE-VOLUME STACKING WITHOUT POLARITY SWITCHING

Several methods have been reported for performing on-column concentrat ion for sensitivity enhancement in highperformance capillary electroph oresis. One technique of interest consists of a large-volume hydrodyna mic injection, followed by the removal of the large plug of low conduc tivity sample matrix from the capillary. In this work, this removal is performed using the redissolution of an electroosmotic flow modifier that will act as a pump, without the need for polarity switching. The performance of this method is evaluated and optimized for the separati on of arsenious acids. Then, the possibility of the quantitative aspec t of this stacking procedure is discussed.