Electrically driven capillary liquid chromatography at ambient pressure

Abstract

The applicability of electrochromatography at ambient pressure is demonstrated on capillaries packed with 3-μm reversed phase particles. The efficiency of the columns is good; reduced plate heights close to 2 were found. The effects of the buffer concentration on the plate height, the electroosmotic flow, and the current were investigated. The plate height appears to increase with decreasing buffer concentration. From this behaviour and from the relative large obstruction factors found, it can be concluded that considerable flow arises through the interconnected pores of the particles under electro drive. The performance under pressure and electrically driven conditions was compared, which revealed that with capillary electrochromatography (CEC) two times more plates can be generated than with pressure drive in the same time. The applicability of CEC for ion pair systems is demonstrated with the separation of nucleobases and nucleosides using sodium dodecyl sulfate as surfactant. © 1998 John Wiley & Sons, Inc. J Micro Sep 10: 41–49, 1998