Chitosan-Functionalized Methacrylate Monoliths for Mixed-Mode Hydrophilic/Electrostatic Interaction Capillary Liquid Chromatography

Abstract

Chitosan stands as a sustainable, active, and eco-friendly biomass that meets eight aspects of green chemistry principles. The chitosan-based liquid chromatography stationary phase provides superior physiochemical properties including a cationic hydrophilic surface, porosity, and mechanical strength; however, it lacks solubility in an organic solvent. A low-cost one-pot in situ free radical polymerization strategy was used to fabricate chitosan-functionalized methacrylate monolithic columns (Ch-GMA-co-EDMA) with hydrophilic and electrostatic properties. The polymerization mixtures were systematically optimized using mixture design to study the effects of compositions on flow-through processes involving porosity and permeability. The chitosan-functionalized methacrylate monomer and monolithic columns were characterized by using ATR-FTIR, TGA, DGA, and SEM. The obtained columns provide high chromatographic performance and satisfactory selectivity for organic polar, neutral, and charged compounds such as phenols, nucleic bases, nucleosides, and anionic pesticides. The results revealed that the amino and hydroxyl moieties of the chitosan monoliths functioned for both hydrophilic as well as electrostatic trapping of polar compounds, additionally promoting hydrogen bonding interaction with the analytes.