Fabrication of monolithic capillary columns with inner diameter 50-530 μm employing a mixture of pentaerythritol tetraacrylate and polyhedral oligomeric silsesquioxane-methacrylate as crosslinkers

Construction of amine-rich coating utilizing amine curing reaction of triglycidyl isocyanate with triethylenetetramine on the surface of poly(styrene-divinylbenzene) microspheres for preparation of anion exchange stationary phase

Epoxy resins, as important thermosetting polymers, exhibit excellent adhesion to various substrates. In view of this, reticulate coating of triglycidyl isocyanate with triethylenetetramine was introduced onto the surface of poly(styrene-divinylbenzene) utilizing amine curing reaction to obtain poly(styrene-divinylbenzene)@triglycidyl isocyanate-triethylenetetramine composite microspheres. The amino groups and epoxy groups of triglycidyl isocyanate-triethylenetetramine endowed poly(styrene-divinylbenzene) with good reactivity, which could be quaternized under mild conditions to obtain an anion exchange chromatographic stationary phase. The quaternized poly(styrene-divinylbenzene)@triglycidyl isocyanate-triethylenetetramine was characterized by scanning electron microscope, Fourier-transform infrared spectroscopy, N2 adsorption-desorption experiment, et al. The chromatographic performance of the customized column was evaluated by separating seven conventional anions, organic weak acids, and carbohydrates. Poly(styrene-divinylbenzene)@triglycidyl isocyanate-triethylenetetramine possesses the uniform size of poly(styrene-divinylbenzene) microspheres and good reactivity of triglycidyl isocyanate-triethylenetetramine, which offers a flexible strategy for the preparation of anion exchange stationary phase. The column exhibits excellent chemical and mechanical stability and chromatographic performance. Finally, the column was successfully applied for the determination of nitrite in pickles.