Striped covalent organic frameworks modified stationary phase for mixed mode chromatography

Area of Science:

• Materials Science
• Analytical Chemistry
• Chromatography

Background:

• Covalent organic frameworks (COFs) show promise for chromatographic separation due to their unique structures.
• The application of COF materials as chromatographic stationary phases is an emerging field.

Purpose of the Study:

• To develop a novel mixed-mode stationary phase based on modified COF materials for high-performance liquid chromatography (HPLC).
• To investigate the separation capabilities and retention mechanisms of the synthesized SiO2@COF material.

Main Methods:

• Silica was modified with benzene-1,4,5-tetracarboxylic dianhydride (PMDA) and 1,3,5-tris-(4-aminophenyl)triazine (TAPT) monomers via a one-pot synthesis to create SiO2@COF.
• Characterization was performed using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), elemental analysis (EA), and powder X-ray diffraction (XRD).
• The separation performance for polar and nonpolar analytes was evaluated using HPLC, and retention mechanisms were studied by analyzing mobile phase effects.

Main Results:

• Characterization confirmed the successful synthesis and structural properties of the SiO2@COF material.
• The SiO2@COF stationary phase demonstrated effective separation of both polar and nonpolar analytes in HPLC.
• Analysis of retention mechanisms revealed multiple interaction modes, including hydrophobic, hydrophilic, hydrogen bonding, and π-π interactions.

Conclusions:

• The developed SiO2@COF stationary phase exhibits robust mixed-mode separation capabilities.
• This material holds significant potential for the analysis of complex samples in chromatography.