Department of Polymer Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyu-ku, Kyoto, 606-8585, Japan.
J Chromatogr A. 2010 Jan 1;1217(1):89-98. doi: 10.1016/j.chroma.2009.11.019. Epub 2009 Nov 10.
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.
研究了甲基三甲氧基硅烷（MTMS）与四甲氧基硅烷（TMOS）的进料比，以改善内径为 100-μm 的混合整体式硅胶毛细管柱在 HPLC 中的性能，MTMS/TMOS（v/v）的范围为 10/90-25/75。还通过调整 PEG 的量来控制渗透性（K=2.8x10(-14)-6.9x10(-14)m(2))来改变粒径。对那些经过十八烷基硅烷化处理的毛细管柱的性能进行评估后发现，随着进料中 MTMS 含量的增加，保留因子（k）增加，空间选择性α（三联苯/邻三联苯）降低。从尺寸排阻色谱（SEC）和反相特性的结果可以看出，进料比的影响也反映在 C18 固定相的孔隙率和疏水性上。在新的制备条件下制备的整体式硅胶毛细管柱能够在流动相乙腈/水=80/20、线性速度为 2mm/s 的条件下，使己基苯的板高达到 4.6-6.0μm。因此，通过降低 MTMS/TMOS 比并增加进料中的总硅烷浓度，可以在保持类似保留因子范围的情况下，制备出性能高于先前报道的混合整体式硅胶毛细管柱。
