title: The performance of hybrid monolithic silica capillary columns prepared by changing feed ratios of tetramethoxysilane and methyltrimethoxysilane.
abstract: The effect of a feed ratio of methyltrimethoxysilane (MTMS) to tetramethoxysilane (TMOS) was studied to improve the performance of a hybrid monolithic silica capillary column with 100-mum i.d. in HPLC in a range MTMS/TMOS (v/v)=10/90-25/75. The domain size was also varied by adjusting the amount of PEG to control permeability (K=2.8x10(-14)-6.9x10(-14)m(2)). Evaluation of the performance for those capillary columns following octadecylsilylation proved an increase in retention factor (k) and a decrease in steric selectivity alpha(triphenylene/ortho-terphenyl) with the increase in MTMS content in the feed. The effect of the feed ratio was also observed in porosity and hydrophobic property of the C18 stationary phase from the results of size exclusion chromatography (SEC) and reversed phase characterization. The monolithic silica capillary columns prepared under new preparation conditions were able to produce a plate height of 4.6-6.0microm for hexylbenzene in a mobile phase acetonitrile/water=80/20 at a linear velocity of 2mm/s. Consequently, it was possible to prepare hybrid monolithic silica capillary columns with higher performance than those reported previously while maintaining the retention factors in a similar range by reducing the MTMS/TMOS ratio and increasing the total silane concentration in feed.
authors: Department of Polymer Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyu-ku, Kyoto, 606-8585, Japan. Takeshi.Hara@phys.chemie.uni-giessen.de
authors: Takeshi
authors: T
authors: Hara
authors: Satoshi
authors: S
authors: Makino
authors: Yuta
authors: Y
authors: Watanabe
authors: Tohru
authors: T
authors: Ikegami
authors: Karin
authors: K
authors: Cabrera
authors: Bernd
authors: B
authors: Smarsly
authors: Nobuo
authors: N
authors: Tanaka
mesh_terms: D002850:Chromatography, Gel / Q000295:instrumentation*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D016062:Porosity; D012117:Resins, Synthetic / Q000737:chemistry; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D012117:Resins, Synthetic; D012821:Silanes; C071718:methyltrimethoxysilane; C061205:tetramethoxysilane; D012822:Silicon Dioxide