Chinese Journal of Chromatography

• Articles • Previous Articles     Next Articles

Chiral Separation of Doxazosin and Its Intermediate by Capillary
Electrophoresis Using Tetramethylammonium Hydroxide to Control Electroosmotic Flow

CHENG Yushan, YANG Xiaolan, YU Yu   

  1. Department of Pharmaceutical Chemistry and Biology Material, Chongqing Medical
    University, Chongqing 400016, China
  • Received:2007-01-26 Revised:2007-04-15 Online:2007-07-30 Published:1985-06-25
  • Contact: Yu Yu

Abstract: A capillary electrophoretic method for the enantiomeric separations of doxazosin and its intermediate was developed. Several tetraalkylammonium reagents were examined for controlling the electroosmotic flow in order to improve resolution of the enantiomers. Tetramethylammonium hydroxide (TMB) was found more suitable than tetrabutylammonium hydroxide (TAB) or hexadecyltrimethylammonium bromide (CTAB) for the enantiomer separation. In addition, the effects of the pH value, the separation voltage and the concentration of the sodiumdihydrogen phosphate on the chiral separation were investigated. A buffer containing 60 mmol/L sodium dihydrogen phosphate (pH 2.2), 30 mmol/L TMB and 12 mmol/L β-cyclodextrin (β-CD) resulted in the baseline separation of the doxazosin enantiomers and its intermediate enantiomers. It showed that the presence of TMB was essential in some chiral separations that were previously not achieved by only using the β-CD as a chiral selector.

Key words: doxazosin and its intermediate, electroosmotic flow, enantiomer separation , tetramethylammonium hydroxide, capillary electrophoresis (CE)