An efficient strategy for preparation of sulfobutylether-β-cyclodextrin chiral stationary phases for liquid...

Chiral separation of pharmaceuticals remains a critical challenge in analytical chemistry due to identical physicochemical properties of enantiomers. Chemically bonded Chiral Stationary Phases (CSPs) generally offer superior stability and solvent compatibility compared to physically adsorbed CSPs. Although cyclodextrin-based CSPs are widely used, chemically bonded SBE-β-CD CSPs remain unexplored. This paper reported an effective method for preparing SBE-β-CD CSPs by chemical bonding for the first time. SBE-β-CD CSPs (degree of substitution 1.02, 6.34, 11.38) were synthesized using a simple "one-pot" reaction in a solvent system comprising an ionic liquid and pyridine. Prepared SBE-β-CD CSPs were thoroughly characterized by ¹H nuclear magnetic resonance spectroscopy (¹H NMR), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and elemental analysis (EA). Effects of various factors, including degree of substitution of SBE-β-CD, buffer salts, pH and temperature were investigated. Chromatographic performance was evaluated under reversed-phase chromatographic conditions with 33 racemates. Notably, SBE_11.38-β-CD CSP exhibited exceptional enantioselectivity, achieving a resolution (Rs) of 9.56 for voriconazole within 15 min. Additionally, SBE-&-CD CSPs also showed good stability and reproducibility after repeated injections. A novel ionic liquid-pyridine composite solvent system has been successfully employed in synthesis of covalently bonded SBE-β-CD CSP, establishing a significant methodological reference for subsequent development of chiral separation materials. This work demonstrates substantial potential of SBE-β-CD CSPs in enantiomeric resolution.