Many amino acids and their derivatives have been used previously as chiral selectors in thin layer chromatography. Herein, we reported the synthesis, characterization, and chromatographic evaluation of a new modified stationary phase based on (S)-3-(aminomethyl)-5-methylhexanoic acid (also known as pregabalin) as an amino acid ligand bonded to the silica surface via triazine attachment. SC-2P (silica-cyanuric-2-pregabalin) is a bonded silica stationary phase prepared by direct binding of the pre-synthesized cyanuric-2-pregabalin organic ligand on the chlorinated silica surface. FT-IR and UV diffuse reflection spectroscopy (UV-DRS) were used to characterize the synthesized bonded phase, and the specific surface area was determined using the methylene blue Langmuir isotherm method to be 147.04 m2/g. TLC plates were prepared from a slurry of this synthesized material with 2 mM of Cu2+ as a selector additive, and the chromatographic characteristics of these plates were investigated to separate a ternary mixture of o-, m-, and p-nitrophenol as structural isomers, and a racemic mixture of (±)-ibuprofen as stereoisomers. Solvent systems of n-hexane:dichloroethane:n-propanol (75:20:5, v/v/v) and Dichloroethane:acetonitrile (90:10, v/v) were selected as mobile phases for nitrophenol and ibuprofen mixtures, respectively. The successful separation was densitometrically confirmed, and retardation factors (Rf) were determined for o-, m-, and p-nitrophenol at 320 nm to be 0.83, 0.45, and 0.28, and for R(−)-, S(+)-ibuprofen at 220 nm to be 0.43 and 0.63, respectively. The synthesis, characterization, and chromatographic evaluation of SC-2P were reported in this article. SC-2P was used with copper ions to form in situ ligand exchange reagent (LER), which was successfully employed to solve an isomeric mixture of nitrophenol and a racemic mixture of (±)-ibuprofen. The synthesized stationary phase showed high repeatability with minimum Rf shifts between batches.

中文翻译：

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基于氨基酸衍生物作为TLC固定相的新型键合硅胶，用于解决硝基苯酚结构异构和布洛芬立体异构

许多氨基酸及其衍生物以前已用作薄层色谱中的手性选择剂。本文中，我们报道了一种新的修饰固定相的合成，表征和色谱分析，该固定相基于（S）-3-（氨基甲基）-5-甲基己酸（也称为普瑞巴林）作为结合到二氧化硅表面的氨基酸配体通过三嗪附件。SC-2P（二氧化硅-氰尿酸-2-普瑞巴林）是通过将预先合成的氰尿酸-2-普瑞巴林有机配体直接结合在氯化硅表面上而制备的键合二氧化硅固定相。使用FT-IR和UV漫反射光谱（UV-DRS）表征合成的键合相，并使用亚甲基蓝Langmuir等温线法确定比表面积为147.04 m2 / g。由这种合成材料的浆料（含2 mM Cu2 +作为选择剂）制备TLC板，并研究了这些板的色谱特性，以分离出邻，间和对硝基苯酚为结构异构体的三元混合物，和（±）-布洛芬的外消旋混合物作为立体异构体。选择正己烷：二氯乙烷：正丙醇（75：20：5，v / v / v）和二氯乙烷：乙腈（90:10，v / v）的溶剂系统分别作为硝基苯酚和布洛芬混合物的流动相。光密度法成功分离，并确定320 nm处邻，间和对硝基苯酚的阻滞因子（Rf）为0.83、0.45和0.28，R（-）-，S（+） -布洛芬在220 nm处分别为0.43和0.63。综合，表征，本文报道了SC-2P的色谱分析。SC-2P与铜离子一起形成原位配体交换试剂（LER），该试剂已成功用于解决硝基苯酚的异构体混合物与（±）-布洛芬的外消旋混合物的问题。合成的固定相显示出高重复性，并且批次之间的Rf位移最小。