Min Yi, Sui Zhigang, Liang Zhen, Zhang Lihua, Zhang Yukui
Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, National Chromatographic R. & A. Center, Dalian 116023, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, National Chromatographic R. & A. Center, Dalian 116023, China.
J Pharm Biomed Anal. 2015 Oct 10;114:247-53. doi: 10.1016/j.jpba.2015.05.035. Epub 2015 Jun 1.
Superficially porous particles (SPPs) demonstrate superior efficiency than totally porous particles in chiral separations. In order to obtain high efficiency and fast separation, sub-2 μm SPPs with high surface area are synthesized, and with teicoplanin bonded, such materials are successfully applied into the rapid enantioseparation of native amino acids. In brief, 1.27 ± 0.06 μm nonporous silica particles are prepared by a modified seeded growth method, followed by mesoporous shell fabrication via one-pot templated dissolution and redeposition strategy, and pore size expansion via acid-refluxing. The diameter of the formed SPPs is 1.49 ± 0.04 μm, with the shell thickness as 206 nm. Nitrogen physisorption experiments show that the Brunauer-Emmett-Teller (BET) specific surface area is 213.6 m(2)/g and pore size is 9 nm. After teicoplanin derivatization with bonding capacity as 83.3 μmol/g, the prepared chiral stationary phase is packed into a stainless steel tube with the geometry of 50 mm × 2.1 mm i.d.. In less than 6.4 min, six native amino acids (norleucine, alanine, valine, methionine, leucine, norvaline) are enantioseparated with resolution factors ranging from 1.9 to 5.0. Besides, the resolution for chiral separation is improved with ethanol-water instead of methanol-water as the mobile phase. Moreover, the low temperature gives higher resolution, but longer retention time and higher backpressure. Finally, the effect of flow rate on enantiomeric separation is studied and fast chiral separation within 1 min is obtained with flow rate of 0.4 mL/min. All these results show that the synthesized teicoplanin bonded sub-2 μm SPPs have great potential to achieve the enantioseparation of native amino acids with high resolution and rapid speed.
表面多孔颗粒（SPPs）在手性分离中表现出比全多孔颗粒更高的效率。为了实现高效快速分离，合成了具有高比表面积的亚2微米SPPs，并键合替考拉宁，此类材料成功应用于天然氨基酸的快速对映体分离。简而言之，通过改进的种子生长法制备1.27±0.06微米的无孔二氧化硅颗粒，随后通过一锅法模板溶解和再沉积策略制备介孔壳层，并通过酸回流使孔径扩大。形成的SPPs直径为1.49±0.04微米，壳层厚度为206纳米。氮气物理吸附实验表明，Brunauer-Emmett-Teller（BET）比表面积为213.6平方米/克，孔径为9纳米。替考拉宁衍生化后键合容量为83.3微摩尔/克，将制备的手性固定相填充到内径为50毫米×2.1毫米的不锈钢管中。在不到6.4分钟的时间内，六种天然氨基酸（正亮氨酸、丙氨酸、缬氨酸、甲硫氨酸、亮氨酸、正缬氨酸）实现对映体分离，分离度因子在1.9至5.0之间。此外，以乙醇-水代替甲醇-水作为流动相时，手性分离的分离度得到提高。而且，低温下分离度更高，但保留时间更长且背压更高。最后，研究了流速对映体分离的影响，流速为0.4毫升/分钟时在1分钟内实现了快速手性分离。所有这些结果表明合成的键合替考拉宁的亚2微米SPPs在实现天然氨基酸的高分辨率和快速对映体分离方面具有巨大潜力。
