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

• Published in: Journal of Chromatography A 2009-10, Vol.1216 (44), p.7394-7401
• Main Authors: Watanabe, Yuta, Ikegami, Tohru, Horie, Kanta, Hara, Takeshi, Jaafar, Jafariah, Tanaka, Nobuo
• Format: Article
• Language: English
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical chemistry; Analytical, structural and metabolic biochemistry; Anion-exchange chromatography; Biological and medical sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Inorganic ions; Monolithic silica column; Nucleotides; Other chromatographic methods
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2009.07.012

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 μm at optimum linear velocity ( u) with keeping their high permeability ( K = 9–12 × 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 mm 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 anions in 1.8 min at a linear velocity of 5.3 mm/s with a backpressure of 20 MPa. In terms of van Deemter 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.