Abstract

A new capillary electrophoresis method was applied to chiral separation of three amino acids, including D,L-tryptophan, D,L-tyrosine and D,L-phenylalanine. The chiral resolution was attained in an untreated fused-sillica capillary using a dual chiral selector, which was made up of Cu(II)-L-histidine complex and β-cyclodextrin (CD). The cardinal factors influencing its separation efficiency, such as chiral selectors, buffer pH and applied voltage, were optimized. Best results were acquired by using a buffer consisting of 10 mmol/L Cu(II), 13 mmol/L L-histidine, 8 mmol/L β-CD, 5 mmol/L phosphate adjusted to pH 5.0 and 15 kV applied voltage. All enantiomers were entirely resolved within 20 min with high resolutions of 3.6~6.1. The analysis method was verified through the determination of D,L-tryptophan in terms of linearity, precision and accuracy. And the robustness of this method was proved. The Limit of Detection and Limit of Quantification for both enantiomers were 2.5 and 5 μg/mL, respectively. The method was perfectly applied to the determination of the enantiomeric purity of L-tryptophan. Furthermore, the interaction between Cu(II)-L-histidine complex and β-CD was also studied using Ultraviolet-visible and ¹H NMR spectroscopy to explain the synergistic effect involved. The results illustrated that Cu(II)-L-histidine complex and β-CD played a synergistic role in the enantiomeric separation of chiral drugs, with good prospects for application.

中文翻译：

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铜（II）-L-组氨酸配合物和β-环糊精的组合使用，通过CE对映体分离三种氨基酸，并研究了协同作用。

摘要

一种新的毛细管电泳方法被用于手性分离三个氨基酸，包括D，L-色氨酸，D，L-酪氨酸和D，L-苯丙氨酸。通过使用由Cu（II）-L-组氨酸配合物和β-环糊精（CD）组成的双重手性选择剂，在未处理的熔融石英毛细管中获得手性拆分。优化了影响其分离效率的主要因素，例如手性选择剂，缓冲液pH和施加电压。使用缓冲液（由10 mmol / L Cu（II），13 mmol / L L-组氨酸，8 mmol / Lβ-CD，5 mmol / L磷酸盐调节至pH 5.0和15 kV施加电压）获得最佳结果。所有对映异构体均在20分钟内完全分离，高分辨率为3.6〜6.1。通过测定D，L-色氨酸的线性，精密度和准确性验证了该分析方法。并证明了该方法的鲁棒性。两种对映体的检出限和定量限分别为2.5和5μg/ mL。该方法完全适用于测定L-色氨酸的对映体纯度。此外，还使用紫外可见和紫外光谱研究了Cu（II）-L-组氨酸配合物与β-CD之间的相互作用。¹ H NMR光谱解释了所涉及的协同作用。结果表明，Cu（II）-L-组氨酸配合物和β-CD在手性药物的对映体分离中具有协同作用，具有良好的应用前景。