Analytical and Bioanalytical Chemistry

, Volume 391, Issue 7, pp 2551–2556

Anion exchange silica monolith for capillary liquid chromatography


    • Department of Chemistry, Faculty of ScienceUniversiti Teknologi Malaysia
  • Yuta Watanabe
    • Department of Biomolecular EngineeringKyoto Institute of Technology
  • Tohru Ikegami
    • Department of Biomolecular EngineeringKyoto Institute of Technology
  • Kosuke Miyamoto
    • Department of Biomolecular EngineeringKyoto Institute of Technology
  • Nobuo Tanaka
    • Department of Biomolecular EngineeringKyoto Institute of Technology
Technical Note

DOI: 10.1007/s00216-008-2063-3

Cite this article as:
Jaafar, J., Watanabe, Y., Ikegami, T. et al. Anal Bioanal Chem (2008) 391: 2551. doi:10.1007/s00216-008-2063-3


An anion exchange monolithic silica capillary column was prepared by surface modification of a hybrid monolithic silica capillary column prepared from a mixture of tetramethoxysilane (TMOS) and methyltrimethoxysilane (MTMS). The surface modification was carried out by on-column copolymerization of N-[3-(dimethylamino)propyl]acrylamide methyl chloride-quaternary salt (DMAPAA-Q) with 3-methacryloxypropyl moieties bonded as an anchor to the silica surface to form a strong anion exchange stationary phase. The columns were examined for their performance in liquid chromatography (LC) and capillary electrochromatography (CEC) separations of common anions. The ions were separated using 50 mM phosphate buffer at pH 6.6. Evaluation by LC produced an average of 30,000 theoretical plates (33 cm column length) for the inorganic anions and nucleotides. Evaluation by CEC, using the same buffer, produced enhanced chromatographic performance of up to ca. 90,000 theoretical plates and a theoretical plate height of ca. 4 μm. Although reduced efficiency was observed for inorganic anions that were retained a long time, the results of this study highlight the potential utility of the DMAPAA-Q stationary phase for anion separations.

Micro-LC performance evaluation of a strong anion exchange silica monolith column, 100H-MOP-DMAPAA-Q, 33 cm in length, with a mobile phase of 50 mM phosphate buffer, pH 2.8; linear velocity: u = 1.8 mm/s; UV-Vis detection at 254 nm. Sample solution (5 mg/mL of each component, 4 mL) was injected in split flow injection mode at a split ratio of ca. 1:1900 with a pump flow rate of 1.5 mL/min


Anion exchangeSilica monolithMicro liquid chromatographyCapillary electrochromatographyInorganic anions



Capillary electrochromatography




Methyl trimethoxysilane


N-[3-(dimethylamino)propyl]acrylamide methyl chloride-quaternary salt



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© Springer-Verlag 2008