Synthesis and application of a chiral ionic liquid functionalized β-cyclodextrin as a chiral selector in capillary electrophoresis.

A novel chiral ionic liquid functionalized β-cyclodextrin, 6-O-2-hydroxpropyltrimethylammonium-β-cyclodextrin tetrafluoroborate ([HPTMA-β-CD][BF4]), was synthesized and used as a chiral selector in capillary electrophoresis. [HPTMA-β-CD][BF4] not only increased the solubility in aqueous buffer in comparison with the parent compound, but also provided a stable reversal electroosmotic flow, and the enantioseparation of eight chiral drugs was examined in phosphate buffer containing [HPTMA-β-CD][BF4] as the chiral selector. The effects of the [HPTMA-β-CD][BF4] concentration and the background electrolyte pH were studied. Moreover, the chiral separation abilities of β-CD and [HPTMA-β-CD][BF4] were compared and possible mechanisms for the chiral recognition of [HPTMA-β-CD][BF4] are discussed.