Preparation of a zeolite imidazole skeleton–silica hybrid monolithic column for amino acid analysis via capillary electrochromatography

Abstract

We developed a novel, convenient and low-cost one-pot strategy for preparing a zeolitic imidazolate framework-8 (ZIF-8)-silica hybrid monolithic column by adding ZIF-8 directly to a polymer solution of the silica matrix. The simulated stationary phase and monolithic column prepared under optimal conditions were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis nitrogen physisorption and zeta potential. The results obtained confirmed the successful introduction of ZIF-8 into the silica monolithic column, and the prepared monolithic column exhibited good permeability and physicochemical stability. A capillary electrochromatography method was developed based on a ZIF-8-silica hybrid monolithic column through which 15 mixed amino acids, 4 neutral compounds, 4 nipagin esters and 2 chlorinated fungicides were separated in 14, 5, 7 and 6 min, respectively, under optimal conditions. The relative standard deviations retention times and column efficiencies in run-to-run, day-to-day and column-to-column varied in the ranges of 1.90%-2.21%, 2.13%-2.51% and 3.08%-6.65%, respectively, which demonstrated that ZIF-8-silica hybrid monolithic column exhibited satisfactory reproducibility and stability. The incorporation of ZIF-8 into a silica monolithic column is a promising method for preparing novel monolithic columns composed of a metal-organic framework.

Recent developments in capillary and microchip electroseparations of peptides (2021–mid‐2023)

“…Attractive alternatives to the classical CEC columns packed with particulate materials are the monolithic SPs prepared in the form of polymeric columns, silica columns, nanomaterials-based columns, and hybrid columns [175][176][177]. Their advantages are simplicity of their in situ preparation and variety of readily available chemistries for synthesis of monolithic materials.…”