Electrochromatographic Evaluation of a Silica Monolith Capillary Column for Separation of Basic Pharmaceuticals

Electrophoresis. 2005 Feb;26(4-5):790-7. doi: 10.1002/elps.200410174.


A silica-based monolithic capillary column was prepared via a sol-gel process. The continuous skeleton and large through-pore structure were characterized by scanning electron microscopy (SEM). The native silica monolith has been successfully employed in the electrochromatographic separation of beta-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). Column efficiencies greater than 250 000 plates/m for capillary electrochromatography (CEC) separation of basic compounds were obtained. It was observed that retention of basic pharmaceuticals on the silica monolith was mainly contributed by a cation-exchange mechanism. Other retention mechanisms including reversed-phase and normal-phase mechanisms and electrophoresis of basic compounds also played a role in separation. A comparison of the differences between CEC and capillary zone electrophoresis (CZE) separation was also discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Antagonists / isolation & purification
  • Alkaloids / isolation & purification
  • Chromatography, Micellar Electrokinetic Capillary / instrumentation*
  • Coptis / chemistry
  • Corydalis / chemistry
  • Drugs, Chinese Herbal / analysis*
  • Drugs, Chinese Herbal / isolation & purification
  • Electrophoresis, Capillary / methods
  • Hydrogen-Ion Concentration
  • Pharmaceutical Preparations / isolation & purification*
  • Plant Roots / chemistry
  • Silicon Dioxide / chemistry*


  • Adrenergic beta-Antagonists
  • Alkaloids
  • Drugs, Chinese Herbal
  • Pharmaceutical Preparations
  • Silicon Dioxide