Open tubular column coated with a novel zinc-based MOF/imine COF hybrid, for small molecular separation using capillary electrochromatography

Metal organic frameworks (MOFs) and covalent organic frameworks (COFs) represent two burgeoning categories of advanced porous materials that have garnered substantial interest within the scientific community in recent years. Notably, the synergistic effect of MOFs and COFs facilitates their integration into MOF/COF hybrid structures, thereby enhancing performance and broadening their applicability across diverse fields. Herein, we report the development of a novel capillary electrochromatographic coated open tubular column, utilizing a MOF/COF hybrid material (ZIF-93/TpBD) as the stationary phase, to achieve high-resolution separation of six groups of analogues. Both ZIF-93/TpBD-coated open tubular (OT) column and the hybrid stationary phase were characterized using a series of analytical techniques. The outstanding separation performance of the as-prepared OT column was evaluated using alkaline amino acids, sulfonamides, acidic antibiotics, vitamin B, purine compounds and β-blocker analyte groups, under optimal separation conditions. The six groups of analytes achieved baseline separation within 9.5 minutes and achieved high resolution (ranging from 1.50 to 9.71). Furthermore, the run to run, day to day, column to column and batch to batch relative standard deviations of retention time and column efficiency were in the range 0.71-3.91% and 0.49-4.19%, respectively. The ZIF-93/TpBD-coated OT column exhibited remarkable stability after 200 consecutive runs. Finally, a rapid, highly efficient, accurate, and reliable method was developed for the qualitative and quantitative analysis of vitamins B1, B2, B6 and nicotinamide in healthcare settings. This novel hybrid stationary phase, composed of MOF/COF, presents a new avenue for the advancement of chromatographic separation.