Fluorinated covalent‐organic polymers as stationary phase for analysis of organic fluorides by open‐tubular capillary electrochromatography

Abstract

Fluorinated porous materials, which can provide specific fluorine‐fluorine interaction, hold great promise for fluoride analysis. Here, a novel fluorinated covalent‐organic polymer was prepared by using 2,4,6‐tris(4‐aminophenyl)‐1,3,5‐triazine and 2,3,5,6‐tetrafluorotelephtal aldehyde as the precursors and introduced as stationary phase for open‐tubular capillary electrochromatography. The as‐synthesized fluorinated covalent‐organic polymer and the modified capillary column were characterized by infrared spectroscopy, scanning electron microscopy, and energy dispersive X‐ray spectrometry. Based on strong hydrophobic interaction and fluorine–fluorine interaction provided by fluorinated covalent‐organic polymer coating layer, the modified column showed powerful separation selectivity toward hydrophobic compounds, organic fluorides, and fluorinated pesticides. Additionally, the fluorinated covalent‐organic polymer with good porosity and regular shape was uniformly and tightly coated on the capillary inner wall. The obtained highest column efficiency could reach up to 1.2 × 105 plates⋅m−1 for fluorophenol. The loading capacity of the modified column can reach 141 pmol for trifluorotoluene. Besides, the relative standard deviations of retention times for intraday run (n = 5), interday run (n = 3), and between columns (n = 3) were all less than 2.55%. Significantly, this novel fluorinated material‐based stationary phase shows great application potential in fluorides analysis.