CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
Anal Chim Acta. 2021 Jan 25;1143:181-188. doi: 10.1016/j.aca.2020.11.053. Epub 2020 Dec 2.
A facile method for efficient synthesis of core-shell composite material was proposed. In this method, the silica microspheres were co-modified with metal organic framework (MOF-235) and polyethylene glycol polymer (PEG) and used as mixed-mode stationary phase (MOF-235@PEG@silica) for high-performance liquid chromatography. Elemental analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller etc. methods were used to investigate the properties of the core-shell composite material. The MOF-235@PEG@silica stationary phase showed flexible selectivity for the separation of both hydrophilic and hydrophobic compounds especially for the separation of nine alkaloids, which showed superior hydrophilic separation performance than previous MOF-based composite stationary phases. Some factors including the pH of buffer salt, the ratio of organic phase and water phase in the mobile phase have been investigated, suggesting that the chromatographic retention mechanism of the column was a mixed mode of hydrophilic and reversed phase. The composite material also showed excellent chromatographic repeatability with the RSDs of the retention time found to be 0.2%-0.6% (n = 10) and the standard addition test in the actual sample proved that it can be used for practical sample analysis. In short, it provided a general way for preparing MOFs-based composites as mixed-mode chromatographic stationary phases, and changed the current status of MOF-based composite materials as single mode chromatographic stationary phases.
提出了一种简便的核壳复合材料合成方法。在该方法中，介孔硅球同时被金属有机框架（MOF-235）和聚乙二醇聚合物（PEG）进行了共修饰，作为混合模式固定相（MOF-235@PEG@silica）用于高效液相色谱。通过元素分析、扫描电子显微镜、X 射线光电子能谱、傅里叶变换红外光谱和 Brunauer-Emmett-Teller 等方法对核壳复合材料的性能进行了研究。MOF-235@PEG@silica 固定相对亲水和疏水化合物的分离表现出灵活的选择性，特别是对 9 种生物碱的分离，表现出优于以前基于 MOF 的复合固定相的亲水分离性能。还考察了一些因素，包括缓冲盐的 pH 值、流动相有机相和水相的比例，表明该柱的色谱保留机制是亲水和反相的混合模式。该复合材料还表现出出色的色谱重现性，保留时间的 RSD 为 0.2%-0.6%（n=10），实际样品的标准添加测试表明其可用于实际样品分析。总之，该方法为制备 MOFs 基复合材料作为混合模式色谱固定相提供了一种通用方法，改变了当前 MOF 基复合材料作为单一模式色谱固定相的现状。
