Increasing the resolving power of capillary electrophoresis through electroosmotic flow control using radial fields

A method for controlling the electroosmotic flow (EOF) in a capillary is re ported using radial electric fields which vary along the length of the sepa ration capillary. The magnitude of the control is compared to the control a chieved using radial fields which remain constant along the length of the c apillary. The effects of buffer concentration, buffer pH, capillary inner d iameter, and capillary outer diameter on the range of control are also exam ined. The potential for increasing the resolving power of capillary electro phoresis (CE) through the use of radial field control of EOF is demonstrate d through the separation of dansylated leucine and isoleucine. (C) 1999 Joh n Wiley & Sons, Inc.