Large volume stacking of anions in capillary electrophoresis using an electroosmotic flow modifier as a pump

A large volume sample stacking for negative species is performed using an electro-osmotic flow modifier which avoids polarity switching. This method is based on the condition that the electrophoretic mobility of the ions are opposite the electro-osmotic flow. Sample loading does not alter the electrode configuration. The experiment demonstrates the ability of whole-column stacking to enhance the detection of fast-moving ions by 100%.