Mercapto-β-cyclodextrin grafting uniform spherical covalent organic frameworks for enantioseparation in liquid chromatography.

Despite the extensive development of covalent organic frameworks (COFs) as stationary phases for chromatography, the majority of COF-based stationary phases require application by bonding or coating on silica gel due to their irregular morphology, nanoscale particle size and broad particle size distribution, which limits the utilization of COFs in liquid chromatography. To take full advantage of COFs, we synthesized size-controllable spherical COFs (SCOFs) as stationary phases further functionalized by mercapto-β-cyclodextrin (SCOFs@CD). The direct-packed SCOFs-1.5μm column achieved separations of small molecules including monosubstituted aromatics, polycyclic aromatic hydrocarbons, and alkylbenzenes, which showed better column efficiency than the SCOFs-2.0μm column. Furthermore, the SCOFs-1.5μm@CD successfully separated dansulfonyl derivatized branched-chain amino acids (DNS-BCAAs) in HILIC mode. This research expanded the application of SCOFs stationary phases and demonstrated their significant potential in liquid chromatography.