Capillary electrochromatography in anion-exchange and normal-phase mode using monolithic stationary phases

J Chromatogr A. 2001 Aug 3;925(1-2):265-77. doi: 10.1016/s0021-9673(01)01034-2.

Abstract

Hydrophilic macroporous weak and strong anion-exchange stationary phases have been prepared in a monolithic format within untreated fused-silica capillaries by the simple thermally or UV-initiated polymerization of 2-dimethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate and ethylene dimethacrylate in the presence of a binary porogenic mixture of dodecanol and cyclohexanol. The tertiary amino functionalities were then alkylated in situ to afford strong anion-exchangers. These new monolithic stationary phases with optimized porous properties were used for the CEC separation of various organic anions. Thus, a mixture of 2-substituted propionic acid drugs (profens) was separated in 13 min and high column efficiencies of up to 231,000 plates/m were achieved. The separation of substituted benzoic acids indicates that the selectivity results primarily from the anion-exchange interactions, while electrophoretic migration contributes only slightly. In addition, these hydrophilic anion-exchangers are also able to separate weakly acidic, neutral and basic compounds such as phenols, xanthines and aromatic amines in normal-phase electrochromatographic mode.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anion Exchange Resins
  • Chromatography, Ion Exchange / methods*
  • Chromatography, Micellar Electrokinetic Capillary / methods*
  • Temperature

Substances

  • Anion Exchange Resins