Abstract:

Based on the diversity of the retention mechanism, mixed-mode capillary monolithic columns have broad application prospect. In this work, a novel capillary polymer monolithic column was prepared with [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SPE) as monomer, ethylene dimethacrylate (EDMA) as crosslinking agent, azobisisobutyronitrile (AIBN) as initiator and butylalcohol/1,4-butanediol/water as ternary porogens. Under the optimized reaction conditions including the proportion of monomer and porogens, amount of initiator, reaction temperature and polymerization time, the monolithic column showed good mechanical strength up to 10 MPa, high permeability of 2.17×10^-14 m² and good repeatability. The peak area RSDs of column-to-column and batch-to-batch reproducibility were 1.0% and 4.6%, respectively. Finally, the capillary monolithic column was evaluated with polar and non-polar test mixtures. It showed hydrophilic interaction under high organic phase while hydrophobic interaction under low organic phase, indicating it a mixed-mode monolithic column.

Key words: capillary high performance liquid chromatography, capillary monolithic column, mixed-mode, preparation