Preparation of chiral metal–organic framework l-his-MIL-53-NH2@SiO2 composite by in situ growth and chiral post-modification strategies for HPLC enantiomeric separation

Abstract

In this work, a chiral core–shell microspheres composite, L-his-MIL-53-NH₂@SiO₂, was prepared through in situ growth and chiral post-modification strategies. The core–shell microspheres were applied as a novel chiral stationary phase for HPLC enantiomeric separation. Various racemates were separated on the L-his-MIL-53-NH₂@SiO₂ packed column using n-hexane/isopropanol as the mobile phase. The chiral column showed excellent separation efficiency for fourteen chiral compounds, including alcohols, alkanes, esters, phenols, ketones, and organic acids. The influence of injection mass and temperature on the separation performance of the chiral column were investigated. The relative standard deviations (n = 5) of the retention time and peak area by repeated separation of benzoin are 0.28% and 0.63%, respectively. The results show that the L-his-MIL-53-NH₂@SiO₂ packed column exhibited good reproducibility and stability. In addition, the chiral resolution ability of the L-his-MIL-53-NH₂@SiO₂ packed column was compared with that of a commercial chiral column (Chiralpak AD-H). The L-his-MIL-53-NH₂@SiO₂ packed column exhibits unique advantages in chiral separations that can be complementary to the commercial chiral column. It was demonstrated that the chiral core–shell microspheres composite L-his-MIL-53-NH₂@SiO₂ prepared based on in situ growth and chiral post-modification strategies has great potential for enantiomeric separation by HPLC.