School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Natural and Agriculture Sciences, University of California, Riverside, CA 92521, USA.
J Chromatogr A. 2019 Feb 22;1587:172-179. doi: 10.1016/j.chroma.2018.12.016. Epub 2018 Dec 10.
Capillary column packed with silica colloidal crystals (SCC) exhibits great efficiency in liquid chromatography because of its highly-ordered structure and extremely narrow channels (about hundred nanometer in diameter) between the particles. However, problems arise due to the extremely high back-pressure created with its dense packings. It is also a challenge to prepare a stable SCC column with an appropriate length for chromatographic separation on a commercial instrument. We have synthesized monodispersed, sub-micron SiO particles bonded with C18 functionality and fabricated SCC capillary columns up to 100 mm in length. The packing materials in the column displayed Bragg diffraction with blueish color under irradiation with white light, indicating the formation of SCC. The column performance was evaluated using pressurized capillary electrochromatography (pCEC) and column efficiencies of more than a hundred thousand plates per column (plate height < 1 μm) were achieved using peptide as a sample. The run-to-run reproducibility expressed with RSD in terms of retention time and peak area for aromatic compounds were less than 0.076% and 1.96%, respectively. These results demonstrate that the combination of pCEC and SCC columns may provide an innovative analytical technique with extraordinary efficiency, resolution and speed for the separation of complex samples.
用硅胶胶体晶体（SCC）填充的毛细管柱在液相色谱中具有很高的效率，因为其具有高度有序的结构和颗粒之间极窄的通道（直径约为一百纳米）。然而，由于其密集的填充产生的极高背压，也会出现问题。在商业仪器上进行色谱分离时，制备具有适当长度的稳定 SCC 柱也是一个挑战。我们已经合成了单分散的、亚微米级的 SiO 颗粒，并与 C18 功能键合，制备了长达 100mm 的 SCC 毛细管柱。在白光照射下，柱内的填充材料显示出布拉格衍射，呈现出蓝色，表明 SCC 的形成。使用加压毛细管电色谱（pCEC）评估了柱性能，使用肽作为样品，实现了超过每柱一百万板（板高<1μm）的柱效。用保留时间和峰面积的 RSD 表示的运行间重现性对于芳香族化合物分别小于 0.076%和 1.96%。这些结果表明，pCEC 和 SCC 柱的组合可能为分离复杂样品提供一种具有非凡效率、分辨率和速度的创新分析技术。
