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, Gansu 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, Gansu 730000, China.
J Chromatogr A. 2022 May 24;1671:463011. doi: 10.1016/j.chroma.2022.463011. Epub 2022 Apr 1.
The micropores of the metal-organic frameworks (MOFs) endow with the advantages of size selectivity and large specific surface area, etc., but they limit their applications toward the control of diffusion and transport processes. Here, we report a strategy to prepare the hierarchical porous material, functional defect, which allows incorporation of L-Cysteine in the MOF by defect-loading. Silica microspheres were modified with these materials to form core-shell composites and used as mixed-mode stationary phases for chromatographic separations. Compared with the traditional MOFs-based stationary phase, it exhibited superior efficiency and selectivity for separation of various analytes and highlighted the role of defect of MOFs and function of L-Cysteine. In addition to the rapid separation of hydrophobic compounds, the stationary phase showed great potential in the separation of hydrophilic analytes, especially for separation of ten carbohydrates and eight sulfonamides. It showed excellent chromatographic reproducibility and stability, and the repeatability of preparation was investigated by relative standard deviations of retention time and/or column efficiency of objective compounds, which was among different batches less than 1.81%. This demonstration provided deep understanding of separation mechanism between MOF-based composites with functional defect and analytes, and stimulated the wide applications of such defective MOFs complexes in separations and analysis.
金属-有机骨架（MOFs）的微孔赋予了其尺寸选择性和大比表面积等优点，但这也限制了它们在扩散和传输过程控制方面的应用。在这里，我们报告了一种制备分级多孔材料的策略，即功能缺陷，通过缺陷负载允许 L-半胱氨酸掺入 MOF。用这些材料对二氧化硅微球进行修饰，形成核壳复合材料，并用作色谱分离的混合模式固定相。与传统的基于 MOF 的固定相相比，它在分离各种分析物时表现出更高的效率和选择性，并突出了 MOF 的缺陷和 L-半胱氨酸的功能的作用。除了快速分离疏水性化合物外，该固定相在分离亲水性分析物方面也具有巨大的潜力，特别是用于分离十种碳水化合物和八种磺胺类药物。它表现出出色的色谱重现性和稳定性，通过目标化合物的保留时间和/或柱效的相对标准偏差来研究制备的重复性，在不同批次之间小于 1.81%。该研究为基于具有功能缺陷的 MOF 复合材料与分析物之间的分离机制提供了深入的了解，并激发了此类有缺陷的 MOF 配合物在分离和分析中的广泛应用。
