Chiral covalent organic framework-monolith as stationary phase for high-performance liquid chromatographic enantioseparation of selected amino acids

The separation of amino acid (AA) enantiomers shows significance for chemistry, food, and biology, but remains challenging due to their similar properties. A promising nanoporous chiral covalent organic framework (COF) as a stationary phase for high-performance liquid chromatography (HPLC) suffers from the irregularity and widely distributed particle size of the chiral COF. Herein, we show the facile preparation of a chiral COF-monolith as a stationary phase for HPLC enantiomeric separation of AAs via orthogonal experiments. The CTzDa-monolith is prepared by the incorporation of the model chiral COF named CTzDa into the porous poly(ethylene dimethacrylate-co-methacrylate) monolith and reveals great permeability and mechanical stability. The corresponding CTzDa-monolithic column gives better chiral HPLC separation of AAs than the commercial Poroshell 120 chiral-T column. Thermal dynamic analysis and molecular docking calculations imply the involvement of stereoscopic hydrogen, π-π, and van der Waals interactions between the CTzDa and AAs during HPLC enantioseparation. The facile incorporation of the chiral COF into the porous monolith will promote the potential of a chiral COF as a stationary phase for HPLC. Graphical abstract