title: Electrochromatographic evaluation of a silica monolith capillary column for separation of basic pharmaceuticals.
abstract: A silica-based monolithic capillary column was prepared via a sol-gel process. The continuous skeleton and large through-pore structure were characterized by scanning electron microscopy (SEM). The native silica monolith has been successfully employed in the electrochromatographic separation of beta-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). Column efficiencies greater than 250 000 plates/m for capillary electrochromatography (CEC) separation of basic compounds were obtained. It was observed that retention of basic pharmaceuticals on the silica monolith was mainly contributed by a cation-exchange mechanism. Other retention mechanisms including reversed-phase and normal-phase mechanisms and electrophoresis of basic compounds also played a role in separation. A comparison of the differences between CEC and capillary zone electrophoresis (CZE) separation was also discussed.
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
authors.forename: Chuanhui
authors.initials: C
authors.lastname: Xie
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.|College of Chemistry & Molecular Sciences, Wuhan University, Wuhan, China.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Hu
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xiao
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
authors.forename: Xingye
authors.initials: X
authors.lastname: Su
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Dong
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
authors.forename: Ruijun
authors.initials: R
authors.lastname: Tian
authors.affiliation: College of Chemistry & Molecular Sciences, Wuhan University, Wuhan, China.
authors.forename: Zhike
authors.initials: Z
authors.lastname: He
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000302:isolation & purification; D000470:Alkaloids / Q000302:isolation & purification; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation*; D039323:Coptis / Q000737:chemistry; D031311:Corydalis / Q000737:chemistry; D004365:Drugs, Chinese Herbal / Q000032:analysis* / Q000302:isolation & purification; D019075:Electrophoresis, Capillary / Q000379:methods; D006863:Hydrogen-Ion Concentration; D004364:Pharmaceutical Preparations / Q000302:isolation & purification*; D018517:Plant Roots / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D000319:Adrenergic beta-Antagonists; D000470:Alkaloids; D004365:Drugs, Chinese Herbal; D004364:Pharmaceutical Preparations; D012822:Silicon Dioxide
references.citation: Nakanishi, K., Soga, N., J. Non Cryst. Solids 1992, 1, 1-13.
references.citation: Nakanishi, K., Soga, N., J. Non Cryst. Solids 1992, 1, 14-24.
references.citation: Minakuchi, H., Nakanishi, K., Soga, N., Ishizuka, N., Tanaka, N., Anal. Chem. 1996, 68, 3498-3451.
references.citation: Allen, D., El Rassi, Z., J. Chromatogr. A 2004, 1029, 239-247.
references.citation: Allen, D., El Rassi, Z., Electrophoresis 2003, 24, 408-420.
references.citation: Chen, Z., Ozawa, H., Uchiyama, K., Hobo, T., Electrophoresis 2003, 24, 2550-2558.
references.citation: Chen, Z., Hobo, T., Anal. Chem. 2001, 73, 3348-3357.
references.citation: Chankvetadze, B., Yamamoto, C., Okamoto, Y., Chem. Lett. 2003, 32, 850-851.
references.citation: Chankvetadze, B., Yamamoto, C., Tanaka, N., Nakanishi, K., Okamoto, Y., J. Sep. Sci. 2004, 27, 905-911.
references.citation: Smith, N. W., Evans, M. B., Chromatographia 1995, 41, 197-203.
references.citation: Fu, H., Jin, W., Xiao, H., Xie, C., Guo, B., Zou, H., Electrophoresis 2004, 25, 600-606.
references.citation: Fu, H., Xie, C., Xiao, H., Dong, J., Hu, J., Zou, H., J. Chromatogr. A 2004, 1044, 237-244.
references.citation: Law, B., J. Chromatogr. 1987, 407, 1-18.
references.citation: Bidlingmeyer, B. A., Del Rios, J. K., Korpi, J., Anal. Chem. 1982, 54, 442-457.
references.citation: Law, B., Gill, R., Moffat, A. C., J. Chromatogr. 1984, 301, 165-172.
references.citation: Cox, G. B., Stout, R. W., J. Chromatogr. 1987, 384, 315-336.
references.citation: Wei, W., Luo, G., Hua, G., Yan, C., J. Chromatogr. A 1998, 817, 65-74.
references.citation: Lai, E. P. C., Dabek-Zlotorzynska, E., Electrophoresis 1999, 20, 2366-2372.
references.citation: McKeown, A. P., Euerby, M. R., Johnson, C. M., Koeberle, M., Lomax, H., Rithie, H., Ross, P., Chromatographia 2000, 52, 777-786.
references.citation: Hsu, H. Y., Chen, Y. E., Sheu, S. J., Hsu, C. H., Chen, C. C., Chang, H. C., Chinese Material Medica - A Concise Guide Modern Drug Press, Taipei, 1985, p.  12.
references.citation: Misaki, T., Sagara, K., Ojima, M., Kakizawa, S., Oshima, T., Yoshizawa, H., Chem. Pharm. Bull. 1982, 30, 354-357.
references.citation: Sagare, A. P., Lee, Y. L., Lin, T. C., Chen, C. C., Tsay, H. S., Plant Sci. 2000, 160, 139-147.
references.citation: Sagara, K., Ito, Y., Ojima, M., Oshima, T., Suto, K., Misaki, T., Itokawa, H., Chem. Pharm. Bull. 1985, 33, 5369-5374.
references.citation: Okopski, J. V., J. Clin. Pharm. Ther. 1987, 12, 369-388.
references.citation: Knox, J. H., Grant, I. H., Chromatographia 1991, 32, 317-328.
references.citation: Wu, J. T., Huang, P., Li, M. X., Lubman, D. M., Anal. Chem. 1997, 69, 2908-2913.
references.citation: Ye, M., Zou, H., Liu, Z., Ni, J., Zhang, Y., Sci. China (Series B) 1999, 42, 639-648.