Improvement of separation efficiencies of anion-exchange chromatography using monolithic silica capillary columns modified with polyacrylates and polymethacrylates containing tertiary amino or quaternary ammonium groups

Anion-exchange(AEX) columns were prepared by on-column polymerization of acrylates and methacrylates containing tertiary amino or quaternary ammonium groups on monolithic silica in a fused silica capillary modified with anchor groups. The columns provided a plate height (H) of less than 10 mu m at optimum linear velocity (u) with keeping their high permeability (K=9-12 x 10(-14) m(2)) Among seven kinds of AEX columns, a monolithic silica column modified with poly(2-hydroxy-3-(4-methylpiperazin-1-yl)propyl methacrylates) (HMPMA) showed larger retentions and better selectivities for nucleotides and inorganic anions than the others. The HMPMA column of 410 mill length produced 42 000-55 000 theoretical plates (N) at a linear velocity of 0 97 mm/s with a backpressure of 3.8 MPa. The same column could be employed for a fast separation of inorganic amons in 18 min at a linear velocity of 5.3 mm/s with a backpressure of 20 MPa. In terms of van Deemtet plot and separation impedance, the HMPMA column showed higher performance than a conventional particle-packed AEX column. The HMPMA column showed good recovery of a protein, trypsin inhibitor. and it was applied to the separation of proteins and tryptic digest of bovine serum albumin (BSA) in a gradient elution. to provide better separation compared to a conventional particle-packed AEX Column (C) 2009 Published by Elsevier B V.