Improved chromatographic performances of glycidyl methacrylate anion-exchange monolith for fast nano-ion exchange chromatography.

An efficient and reproducible photopolymerized poly(glycidyl methacrylate-co-ethylene dimethacrylate) was synthesized in Teflon-coated fused-silica capillaries (100 µm id) and functionalized by reaction of triethylamine with reactive epoxy groups. We report here the successful transfer of a standard polymerization mixture optimized for the thermally initiated synthesis of glycidyl-based monolith to photo-induced polymerization. The monolith obtained after optimization of the photo-initiation conditions was characterized in reverse-phase chromatography evaluating its suitability in terms of efficiency, retention and hydrodynamic permeability. Reproducibility of the photo-induced procedure was satisfactory with RSD below 6% for retention and efficiency and slightly higher for hydrodynamic permeability (12%). The functionalized generic support was then used in nano-ion-exchange chromatography. Efficiencies up to 75,000 plates/m, ion-exchange capacity of 8 nano-equivalents/cm of monolithic column, with a combination of a satisfactory hydrodynamic permeability allowed to perform fast separations of five inorganic anions in <3 min maintaining baseline resolution. The efficiency of the monolith was not retention-dependent, demonstrating its wide range of possible applications for highly retained anions.