Preparation and modeling study of novel carboxymethyl-β-cyclodextrin silica hybrid monolithic column for enantioseparations in capillary electrochromatography

In this paper, an anionic carboxymethyl-beta-cyclodextrin (CM-beta-CD) silica hybrid monolithic column was first prepared by "one-pot" sequential reaction. The chiral stationary phase (CSP) and prepared monolithic column were demonstrated by fourier transform infrared (FT-IR), nuclear magnetic resonance (H-1 NMR) and scanning electron microscope (SEM). To obtain better separation efficiency, the columns' preparation conditions (DMSO, AIBN and PEG) and separation conditions (buffer pH, ACN proportion, separation voltage and buffer solution) were optimized using model analytes. The resulting columns were finally used in chiral separations of ten racemic compounds, and satisfactory separation selectivity was obtained. The RSDs lower than 3.0% were obtained through run-to-run (n = 6), day-to-day (n = 3), and column-to-column determinations (n = 3). Furthermore, the mechanism of chiral recognition was demonstrated using molecular modeling with AutoDock. This proposed method was also well validated with good linearity (>= 0.998), recovery (96.79-97.88%) and repeatability, and was successfully used for enantiomeric impurity detection of S-ofloxacin tablet. As a novel chiral stationary phase, CM-beta-CD was supposed to be a promising prospect in the further analysis of chiral samples.