Key Laboratory of Functional Molecule Design and Interface Process, School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei, 230601, China.
Vrije Universiteit Brussel, Department of Analytical Chemistry, Applied Chemometrics and Molecular Modelling, Laarbeeklaan, 103, B-1090, Brussels, Belgium.
Anal Chim Acta. 2023 Sep 1;1272:341527. doi: 10.1016/j.aca.2023.341527. Epub 2023 Jun 12.
Due to its high chemical stability, sufficient rigidity and zwitterionic ion exchange properties, TiO can be considered as an alternative stationary phase material to SiO for high performance liquid chromatography. TiO stationary phase is usually prepared by coating TiO onto SiO support by sol-gel method. However, in the traditional coating method, in order to overcome the rapid hydrolysis rate of tetrabutyl orthotitanate, only a very low concentration of tetrabutyl orthotitanate can be used, resulting in a low loading of TiO on the support.
TiO core-shell spheres with a good monodispersity were prepared using 0.25 mol L tetrabutyl orthotitanate. The specific surface area, pore volume, pore diameter and TiO loading of the TiO core-shell spheres were 66 m g, 0.15 cm g, 9.8 nm and 57%, respectively. The core-shell spheres were derivatized with n-octadecyltrichlorosilane and then packed into a stainless steel column to test the separation performance for neutral, basic and acidic samples in liquid chromatography. A baseline separation of polyaromatic hydrocarbons was achieved, showing a column efficiency for fluorene of 118075 plates m. The prepared stationary phase was also used to separate acidic and basic mixtures, and column efficiencies of 54500 and 25836 plates m were obtained for N,N-dinitroaniline and p-chlorophenol, respectively. The relative standard deviations of the retention times of polyaromatic hydrocarbons for run-to-run, day-to-day and column-to-column repeatability were all below 5.1%.
This work demonstrated that TiO can be coated in the pores of the shell of SiO core-shell spheres with high TiO loading using a high concentration of tetrabutyl orthotitanate as the titania source. The experimental results show that the TiO coated core-shell spheres can be a good alternative stationary phase for liquid chromatography.
由于 TiO 具有化学稳定性高、刚性足够和两性离子交换性能，因此可以被视为替代 SiO 的高效液相色谱固定相材料。TiO 固定相通常通过溶胶-凝胶法将 TiO 涂覆在 SiO 载体上制备。然而，在传统的涂覆方法中，为了克服四丁基原钛酸酯的快速水解速率，只能使用非常低浓度的四丁基原钛酸酯，导致 TiO 在载体上的负载量很低。
使用 0.25mol/L 的四丁基原钛酸酯成功制备了具有良好单分散性的 TiO 核壳球。TiO 核壳球的比表面积、孔体积、孔径和 TiO 负载量分别为 66m²/g、0.15cm³/g、9.8nm 和 57%。核壳球用十八烷基三氯硅烷衍生化，然后填充到不锈钢柱中，以测试高效液相色谱中中性、碱性和酸性样品的分离性能。实现了多环芳烃的基线分离，氟芴的柱效达到 118075 板/m。所制备的固定相也用于分离酸性和碱性混合物，对于 N,N-二硝基苯胺和对氯苯酚，分别获得了 54500 和 25836 板/m 的柱效。多环芳烃保留时间的运行间、日间和柱间重复性的相对标准偏差均低于 5.1%。
这项工作表明，可以使用高浓度的四丁基原钛酸酯作为钛源，将 TiO 涂覆在 SiO 核壳球的壳孔中，从而实现高负载量的 TiO 涂覆。实验结果表明，涂覆 TiO 的核壳球可以成为高效液相色谱的一种良好的替代固定相。
