REVERSE DIRECTION ANION CAPILLARY ELECTROPHORESIS - THEORY AND APPLICATION

A new mode for operating capillary electrophoresis for separation of a nions without using buffer modifiers has been demonstrated. Reverse di rection anion capillary electrophoresis, as the new mode is designated , is performed on two anions, nitrate and nitrite, with similar electr ophoretic mobilities at various buffer pH values. Since electroosmotic flow increases as buffer pH is increased, it is shown that resolution is poor at low pH and enhanced at neutral to high pH. Model equations are derived for predicting the resolution and number of theoretical p lates for reverse direction anion capillary electrophoresis. From thes e equations, system efficiency (N) and resolution are plotted as a fun ction of electroosmotic mobility to illustrate how performance can be improved by an increase in electroosmotic flow.