Reversal of enantiomer elution order in capillary electrophoresis using charged and neutral cyclodextrins

Three different techniques for the reversal of the enantiomer elution order in capillary electrophoresis (CE) are reported in this paper. Intrinsic chiral recognition of the chiral selector remains the same in all cases and the reversal of enantiomer elution order is achieved by manipulation of the mobilities of the chiral selector and selectand. The mechanism of the reversal of the enantiomer elution order is described in detail for each particular case. In the first case a reversal of the enantiomer elution order is achieved by modification of the self-mobility of a chiral selector by introduction of an anionic substituent. In the second case the same effect was achieved by changing the pH of the separation buffer and in the third one by combination of the pH change and the reversal of polarity of the high-voltage supply.