Effect of various modes of pressurization on the separation in capillary electrochromatography

In capillary electrophoresis and capillary electrochromatography, the driving factor of the separation is electroosmotic flow (EOF). Pressurized capillary electrochromatography, in which the separation is controlled by EOF as well as the pressure, becomes more and more attractive. We studied the influence of various pressures on capillary electrochromatographic separation. The results reveal that in pressurized capillary electrochromatography, which was performed by EOF combined with the forward and reverse pressure, the main driving factor is still the EOF. It was also found that, when reverse pressure was applied in capillary electrochromatography, the repeatability of the capillary electrochromatographic separation was increased dramatically.