Carboxymethyl‐β‐cyclodextrin and histidine‐zeolitic imidazolate framework‐8 used for enantioseparation of three basic drugs in open‐tubular capillary electrochromatography

Abstract Metal organic frameworks (MOFs) have drawn broad attention as a novel stationary phase due to their highly porous structure, modifiable pores, large specific surface areas, and satisfactory stability. In this paper, histidine‐zeolitic imidazolate framework‐8 (His‐ZIF‐8) synthesized at room temperature was physically coated to the internal surface of the capillary column and the carboxymethyl‐β‐cyclodextrin (CM‐β‐CD) as the chiral selector was chemically bonded to the His‐ZIF‐8@capillary column. The prepared CM‐β‐CD@His‐ZIF‐8@capillary column was used for the enantioseparation of amlodipine, propranolol, and atenolol in capillary electrochromatography. In contrast to the CM‐β‐CD@capillary column without His‐ZIF‐8, the CM‐β‐CD@His‐ZIF‐8@capillary column reveals significantly improved enantiodiscrimination performance for amlodipine ( R s : 0 → 2.29), propranolol ( R s : 0 → 1.69), and atenolol ( R s : 0 → 0.79). His‐ZIF‐8 concentration, buffer pH, buffer concentration, and the proportion of organic modifier were evaluated in detail with enantiomerically separating chiral molecules. The repeatability of intraday, day‐to‐day, and column‐to‐column have been discussed; the result was preferable, and the relative standard deviation (RSD) of separation parameters was <6.7%.