In situ growth of Zr‐based metal‐organic framework UiO‐66‐NH2 for open‐tubular capillary electrochromatography

Abstract The high stability and other properties of Zr(IV)‐based metal organic frameworks(MOFs) make it a promising choice for chromatographic separation, while the application in open‐tubular capillary electrochromatography (OT‐CEC) separation has not been explored yet. Herein, we report the first example of the in‐situ growth of UiO‐66‐NH 2 onto the capillary for open‐tubular capillary electrochromatography. UiO‐66‐NH 2 consists of ZrCl 4 and 2‐amino‐1,4‐benzenedicarboxylic acid, which is highly porous and stable in a variety of solvents. The prepared UiO‐66‐NH 2 modified capillary was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectra (FT‐IR), and the results confirmed the successful growth of the UiO‐66‐NH 2 . The baseline separation of chlorobenzenes, phenoxyacids and two groups of phenols was achieved owing to the combined interaction of π‐π interaction, hydrophobic interaction, molecular sieve effect, electrophoretic migration and hydrogen‐bonding interaction etc. Besides, the prepared capillaries showed good reproducibility, with relative standard deviations (RSDs) for intra‐day, inter‐day and column‐to‐column runs in the range of 1.38–2.60%, 3.39–4.05%, and 3.47–5.03%, respectively. Our work indicates Zr(IV)‐based MOFs are promising materials as stationary phase in CEC separation.