One-pot synthesis of polymer monolithic column by combination of free radical polymerization and azide–alkyne cycloaddition “click” reaction and its application in capillary liquid chromatography

Abstract

Combining free radical polymerization with click chemistry via copper-mediated azide–alkyne cycloaddition (CuAAC) reaction in a “one-pot” process, a facile approach was developed for the preparation of a polymer monolithic column carrying 6-azidohexanoic acid (AHA), which was applied in capillary liquid chromatography (cLC) separations in the mixed-mode. The synthetic procedure was simple, time-saving and without any post modification. The morphology, permeability, and pore properties of the prepared polymer monolithic columns were characterized and the results showed the polymer monoliths have a uniform monolithic structure with high porosity. The retention behavior of the neutral and polar solutes on the polymer monoliths confirmed the successful incorporation of ligand in the monolithic matrix. A series of alkylbenzenes, phenols, and anilines were used to evaluate the chromatographic properties of the polymer monolith in terms of hydrophobic, hydrophilic and cation-exchange interactions. In addition, the poly (AHA-co-propargyl methacrylate-co-ethylene dimethacrylate) (AHA-co-PMA-co-EDMA) monolithic column could be successfully applied to the separation of polycyclic aromatic hydrocarbons (PAHs), nucleosides and nucleobases, alkaloids, peptides and proteins. The reproducibility of the monolithic column was less than 4.0% in terms of relative standard deviation (RSD) of the retention factor. The results demonstrate that the proposed method was an effective alternative for the preparation of the polymer monolith.