Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai, China.
J Chromatogr A. 2012 Jul 20;1247:63-70. doi: 10.1016/j.chroma.2012.05.062. Epub 2012 May 24.
Highly monodisperse 1,4-dimethoxybenzene-bridged organic/inorganic hybrid mesoporous spheres were synthesized by condensation of 1,4-dimethoxy-2,5-bis(triethoxysilyl)benzene using dodecylamine (DDA) and cetyltrimethylammonium bromide (CTAB) as co-templates. The spherical hybrid particles, which have specific surface area of 509 m²/g, pore volume of 0.8 cm³/g and average pore size of 63 Å, were characterized by elemental analysis, SEM, TEM, small angel X-ray scattering, Raman, FT-IR and nitrogen adsorption-desorption analysis. The hybrid material was further chemically modified with C12 chain group via formation of C-O-R bond, which is believed to be far more stable than traditional Si-O-Si bonding type at low pH condition. At the same time, the hybrid silica substrate has been proved to possess the improved chemical stability at high pH. In this way, combination of the hybrid silica substrate and this advanced modification method enable the stationary phase to be used in extended pH range. The chemical stability of this surface modified 1,4-dimethoxybenzene-bridged hybrid stationary phase was evaluated both at low pH (pH=0.95) and high pH (pH=11.0). Some acidic and alkaline pH chromatographic evaluations were performed to illustrate the advantages of the improved chemical stability of this packing material.
高度单分散的 1,4-二甲氧基苯桥联有机/无机介孔球通过使用十二胺（DDA）和十六烷基三甲基溴化铵（CTAB）作为共模板缩合 1,4-二甲氧基-2,5-双（三乙氧基硅基）苯合成。这些具有 509 m²/g 的比表面积、0.8 cm³/g 的孔体积和 63 Å 的平均孔径的球形杂化颗粒通过元素分析、SEM、TEM、小角度 X 射线散射、拉曼、FT-IR 和氮气吸附-脱附分析进行了表征。通过形成 C-O-R 键，杂化材料进一步用 C12 链基团进行化学修饰，与传统的 Si-O-Si 键合类型相比，这种键在低 pH 条件下更加稳定。同时，已经证明杂化二氧化硅基质在高 pH 值下具有更好的化学稳定性。通过这种方式，将杂化二氧化硅基质与这种先进的修饰方法相结合，使固定相能够在更宽的 pH 范围内使用。该表面修饰的 1,4-二甲氧基苯桥联杂化固定相的化学稳定性在低 pH（pH=0.95）和高 pH（pH=11.0）下进行了评估。进行了一些酸性和碱性 pH 色谱评估，以说明这种填充材料改进的化学稳定性的优势。
