Preparation and characterization of methacrylate-based monolith for capillary hydrophilic interaction chromatography

In current study, poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) monolith was successfully prepared for capillary hydrophilic liquid chromatography (cHILIC). The polymerization was optimized by changing the ratio of MAA to EDMA, the type and amount of porogen. The characterization indicated that "hydrophilic" monolithic column possessed homogeneous column bed, good permeability and narrow pore size distribution. Under HILIC mode, the "hydrophilic" monolith prepared with PEG and DMSO showed stronger hydrophilicity than the "hydrophobic" monolith prepared with dodecanol and toluene. Finally, the "hydrophilic" monolith was applied in the separation of tryptic digests of bovine serum albumin (BSA) with cHILIC-ESI-qTOF-MS system. Our results revealed that 49 peptides were identified with 50% sequence coverage under HILIC mode, which was much better than the peptides identified using particulate-packed commercial column with RPLC-ESI-qTOF-MS system or "hydrophobic" monolith with cHILIC-ESI-qTOF-MS system. Taken together, the "hydrophilic" monolithic column prepared in current study, demonstrated the excellent chromatographic performance on the separation of complex samples, which offers the potential application of the monolith on proteomics study.