Improving affinity of boronate capillary monolithic column for microextraction of glycoproteins with hydrophilic macromonomer

Abstract

A novel boronate affinity monolithic capillary was prepared by in-situ polymerization and successfully applied to microextraction (PMME) of glycoproteins. Using functional monomer 3-(acrylamido)phenylboronic acid (AAPBA) and hydrophilic macromonomer oligo (ethylene glycol) methyl ether methacrylate (OEG), crosslinking monomer ethylene glycol dimethacrylate (EDMA) and binary porogens of n-propanol and 1,4-butanediol, poly(AAPBA-co-OEG-co-EDMA) monolith was made with uniform structure and good column permeability. Systematic optimization of preparation conditions were performed, including AAPBA content, the molar ratio of AAPBA to OEG, crosslinking monomer content, n-propanol content in binary porogens. The optimized OEG boronic monolithic column was characterized with infrared absorption spectroscopy, field emission scanning electron microscopy and N2 adsorption experiment. In this study, extraction performance was tested by PMME of horseradish peroxidase (HRP) and ovalbumin (OVA). Compared with the corresponding OEG-free boronate monolith, the recovery of HRP and OVA was significantly improved to 97.51% and 93.97% (RSDs < 5.0%), respectively, which increased by 30.0%. Moreover, the newly developed monolith was further applied for extraction of HRP and OVA from the egg white samples with the recovery of 96.10% and 92.24% (RSDs < 7.5%), respectively. The results suggested that the introduction of hydrophilic macromonomer into boronic material is an effective method to improve the affinity of boronate affinity chromatography to glycoproteins.