Institute of Inorganic Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany; Process Analysis and Technology (PA&T), Reutlingen Research Institute, Reutlingen University, Alteburgstrasse 150, Reutlingen 72762, Germany.
Process Analysis and Technology (PA&T), Reutlingen Research Institute, Reutlingen University, Alteburgstrasse 150, Reutlingen 72762, Germany; Institute of Wood Technology and Renewable Materials, Department of Material Sciences and Process Engineering (MAP), University of Natural Resources and Life Sciences, Gregor-Mendel-Straße 33, Vienna 1180, Austria.
J Chromatogr A. 2023 Aug 30;1705:464190. doi: 10.1016/j.chroma.2023.464190. Epub 2023 Jul 1.
High-performance liquid chromatography is one of the most important analytical tools for the identification and separation of substances. The efficiency of this method is largely determined by the stationary phase of the columns. Although monodisperse mesoporous silica microspheres (MPSM) represent a commonly used material as stationary phase their tailored preparation remains challenging. Here we report on the synthesis of four MPSMs via the hard template method. Silica nanoparticles (SNPs) which form the silica network of the final MPSMs were generated in situ from tetraethyl orthosilicate (TEOS) in the presence of (3-aminopropyl) triethoxysilane (APTES) functionalized p(GMA-co-EDMA) as hard template. Methanol, ethanol, 2-propanol, and 1-butanol were applied as solvents to control the size of the SNPs in the hybrid beads (HB). After calcination, MPSMs with different sizes, morphology and pore properties were obtained and characterized by scanning electron microscopy, nitrogen adsorption and desorption measurements, thermogravimetric analysis, solid state NMR and DRIFT IR spectroscopy. Interestingly, the Si NMR spectra of the HBs show T and Q group species which suggests that there is no covalent linkage between the SNPs and the template. The MPSMs were functionalized with trimethoxy (octadecyl) silane and used as stationary phases in reversed-phase chromatography to separate a mixture of eleven different amino acids. The separation characteristics of the MPSMs strongly depend on their morphology and pore properties which are controlled by the solvent during the preparation of the MPSMs. Overall, the separation behavior of the best phases is comparable with those of commercially available columns. The phases even achieve faster separation of the amino acids without loss of quality.
高效液相色谱法是鉴定和分离物质的最重要的分析工具之一。该方法的效率在很大程度上取决于柱的固定相。虽然单分散介孔硅微球（MPSM）作为固定相是一种常用的材料，但它们的定制制备仍然具有挑战性。在这里，我们通过硬模板法报告了四种 MPSM 的合成。在（3-氨丙基）三乙氧基硅烷（APTES）功能化的 p（GMA-co-EDMA）作为硬模板存在的情况下，从正硅酸乙酯（TEOS）原位生成形成最终 MPSM 的硅纳米颗粒（SNP）。甲醇、乙醇、2-丙醇和 1-丁醇被用作溶剂，以控制混合珠（HB）中 SNP 的尺寸。煅烧后，获得了具有不同尺寸、形貌和孔性能的 MPSM，并通过扫描电子显微镜、氮气吸附和脱附测量、热重分析、固态 NMR 和 DRIFT IR 光谱进行了表征。有趣的是，HB 的 Si NMR 光谱显示出 T 和 Q 基团物质，这表明 SNP 和模板之间没有共价键。MPSM 用三甲氧基（十八烷基）硅烷官能化，并用作反相色谱中的固定相，以分离 11 种不同氨基酸的混合物。MPSM 的分离特性强烈依赖于其形态和孔性能，这是在 MPSM 制备过程中通过溶剂来控制的。总的来说，最佳相的分离行为与市售柱相当。这些相甚至可以在不降低质量的情况下更快地分离氨基酸。
