Simultaneous and sensitive capillary electrophoretic enantioseparation of three β-blockers with the combination of achiral ionic liquid and dual CD derivatives.

Successful simultaneous enantioseparation and sensitive determination of three β-blockers (PIN, OX and PRO), have been achieved by capillary electrophoresis using an achiral ionic liquid, [GTMA]Cl, as a modifier to cooperate with dual CDs containing DM-β-CD and TM-β-CD. The influence of aIL was investigated in details, including various aILs, the concentration of aIL and molar ratio of aIL to CD. The ratio of DM-β-CD to TM-β-CD in dual CDs was also discussed. DM-β-CD and TM-β-CD favor the enantioseparations of PIN/OX and PRO, respectively. Meanwhile, the presence of [GTMA]Cl was found to play a key role in enantioseparations, and it widened the scope of application of DM-β-CD and TM-β-CD. Furthermore, FESI as an effective on-line sample enrichment technique was developed to improve the detection sensitivity. Under the optimum conditions, the detection limits of the three pairs of enantiomers range from 0.10 to 0.65 nM, which are much lower than those in the conventional methods. Eventually, the proposed method was successfully applied to the analysis of spiked urine sample with good recoveries.