1. Recent advances of enantioseparations in capillary electrophoresis and capillary electrochromatography
Huang Lu and Guonan Chen*. Anal. Methods, 2011, 3, 488–508
Commonly, one enantiomer of the analyzed chiral compound is used as the imprinted molecule (also known as template molecule) to prepare MIPs that would show selective chiral recognition towards the original molecule. Ou et al. prepared (5S,11S)-(-)-Troger’s base and L-tetrahydropalmatine molecularly imprinted monolithic columns via in situ thermal-initiated copolymerization of methacrylic acid and ethylene dimethacrylate for the enantioseparation of Troger’s base and tetrahydropalmatine. The results showed that these columns presented high selectivities while the separation efﬁciencies were rather low. Wang et al. fabricated new molecularly imprinted silica-based hybrid monolithic columns via a room temperature ionic liquid-mediated nonhydrolytic sol–gel (NHSG) route for the enantioseparation of zolmitriptan. Three carboxylic acids, triﬂuoromethyl acrylic acid, cinnamic acid, and methacrylic acid, were examined as both the functional monomers and the catalysts for the NHSG condensation. It was found that triﬂuoromethyl acrylic acid took the shortest time. In addition, the porosity was strengthened and the resolution of zolmitriptan enantiomers was improved by adding the ionic liquid. Li et al. fabricated different MIP polymeric monolithic columns via a single step for the enantioseparation of four amino acids and a tyrosine derivative. Except for alanine, successful enantioseparations of all other analytes were obtained by pressurized CEC within 10 min.