Electro-osmotic flow control using back-pressure in capillary electrophoresis

摘要

A separating capillary in a capillary electrophoresis device is less than 20 microns high, in order to restrict the flow rate profile of the EOF to be essentially parabolic. The capillary is preferably rectangular, with a side ratio of at least 2 : 1 and preferably at least 10 : 1, in order to increase the mass flow. A hydrostatic back-pressure is applied to the capillary, in order to reduce or remove the EOF. The back-pressure preferably represents at least 50% of the amplitude of the forward-directed EOF, in order to reduce the EOF and thereby increase the resolution.