Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
Sci Rep. 2022 May 6;12(1):7460. doi: 10.1038/s41598-022-11078-y.
A hydrothermal sol-gel method for reproducible formation of silica nanolayer on the wall of silica capillaries was developed for electrochromatography. The formulation was optimized by observation of uniform gel formation on an optical microscope. The variables of the formulation include types of solvent, water-TEOS ratio, CTAB and urea contents, and mixing method. The procedure produced a coating of silica ca. 100 nm thick layer on the wall of the capillary. Surface morphology of the coating was characterized by SEM, contact angle and chemical composition by FT-IR spectroscopy and X-ray powder diffraction. The coating reduced the electroosmotic mobility producing enhanced separation performance. Eight standard amines (including tyramine and benzhydrylamine, as an internal standard) were separated with peak resolution R ≥ 2 for all adjacent peaks and plate number N ≥ 3.0 × 10 m. Calibration was linear from 5 to 200 µg L, with r > 0.9985 and instrumental LOD of 4.9 μg L. Five samples of food products were diluted and analyzed for the amines using the coated capillary and only tyramine was detected. Intra-day and inter-day precisions were less than 1.2%RSD. Percent recoveries of spiked tyramine in samples were 95 ± 3 to 106 ± 7% (n = 3).
一种水热溶胶-凝胶法被开发用于在硅胶毛细管内壁上重现性地形成硅胶纳米层，用于电色谱。通过在光学显微镜下观察均匀的凝胶形成，对配方进行了优化。配方的变量包括溶剂类型、水-TEOS 比、CTAB 和尿素含量以及混合方法。该程序在毛细管内壁上产生了约 100nm 厚的硅胶涂层。通过 SEM、接触角和 FT-IR 光谱以及 X 射线粉末衍射对涂层的表面形貌、化学组成进行了表征。该涂层降低了电动迁移率，从而提高了分离性能。八种标准胺（包括酪胺和苯甲叉胺，作为内标）均得到了分离，所有相邻峰的峰分辨率 R≥2，板数 N≥3.0×10^5。校准曲线在 5 至 200μg L 范围内呈线性，r＞0.9985，仪器检测限为 4.9μg L。五种食品样品经稀释后，用涂覆的毛细管对胺进行分析，仅检测到酪胺。日内和日间精密度均小于 1.2%RSD。样品中添加的酪胺的回收率为 95±3%至 106±7%（n=3）。
