Electrophoresis, Vol.24, No.15, 2508-2513, 2003
Use of chiral zwitterionic surfactants for enantiomeric resolutions by capillary electrophoresis
The enantiomeric resolution of 1,1'-binaphthyl-2,2'-diamine and Troger's base was investigated using the commercially available zwitterionic surfactants 3-[(3-cholamidopropyl)dimethylammonio]-1 -propanesulphonate (CHAPS) and 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulphonate (CHAPSO). Resolution of the weakly basic chiral probes was achieved using varying concentrations of surfactant, above their critical micellar concentrations, in a phosphate buffer (pH 2.5; 100 mm) to ensure ionisation of the analytes. Both CHAPS and CHAPSO were employed in the absence of additional coselectors or surfactants as sole micellar-forming agents. The addition of organic modifiers, methanol and acetonitrile (ACN), to the background electrolyte (BGE) was found to have a detrimental effect on enantioselectivity presumably by alteration of the phase polarity.
Keywords:capillary electrophoresis;chiral analysis;electrokinetic chromatography;zwitterionic surfactant