Preparation of D‐histidine modified zeolitic imidazolate framework‐90 coated capillary column and its application in open‐tube capillary electrochromatography enantioseparation

Metal‐organic framework materials are a class of novel crystalline porous materials with regular pore structures formed by covalent bonding between metal centers and organic functional groups. Metal‐organic framework materials have attracted great interest in analytical chemistry due to their unique properties such as good stability and permanent porosity. In this work, D‐histidine was used to carry out chiral modification of zeolitic imidazolate framework‐90 under mild conditions, and the D‐histidine modified zeolitic imidazolate framework‐90 coated capillary column was prepared. This chiral capillary column was used to separate epinephrine, norepinephrine, terbutaline, and tryptophan enantiomers. Under optimum conditions, baseline separations were achieved. The intra‐day, inter‐day, and inter‐column relative standard deviations ( n = 3) of the four pairs of enantiomeric migration times were 0.15%–0.56%, 0.74%–2.40%, and 1.93%–3.18%, respectively. Moreover, the D‐histidine modified zeolitic imidazolate framework‐90 coated capillary could be reused for at least 150 runs without significant changes in the separation efficiency and migration time.