Institute of Mass Spectrometry, Ningbo University, Ningbo 315211, P. R. China.
Faculty of Electrical Engineering and Computer Science, Ningbo University, Ningbo 315211, P. R. China.
Anal Chem. 2021 Jan 19;93(2):859-867. doi: 10.1021/acs.analchem.0c03461. Epub 2020 Nov 23.
Chiral analysis is critical to many research fields due to different biological functions of enantiomers in living systems. Although the use of ion mobility spectrometry (IMS) has become an alternative technology in the area of chiral measurements, there is still a lack of a general chiral selector for IMS-based chiral recognition, especially for small chiral molecules. Here, a new method using oligosaccharides as the chiral selector has been developed to discriminate chiral amino acids (AAs) by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS). We analyzed 21 chiral amino acids, including small molecules (e.g., alanine and cysteine). Our data showed that the use of nonreducing tetrasaccharides was effective for the separation of chiral AAs, which differentiated 21 chiral AAs without using metal ions. By further incorporating a copper ion, the separation resolution could be improved to 1.64 on average, which accounts for an additional 52% improvement on top of the already achieved separation in metal-free analysis. These results indicate that the use of tetrasaccharides is an effective strategy for the separation of AA enantiomers by TIMS. The method developed in this study may open up a new strategy for effective IMS-based chiral analysis.
手性分析对于许多研究领域至关重要，因为对映体在生命系统中具有不同的生物学功能。尽管离子淌度谱（IMS）的使用已成为手性测量领域的一种替代技术，但对于 IMS 基手性识别，特别是对于小的手性分子，仍然缺乏通用的手性选择器。在这里，我们开发了一种使用低聚糖作为手性选择器的新方法，通过俘获离子淌度谱-质谱（TIMS-MS）来区分手性氨基酸（AA）。我们分析了 21 种手性氨基酸，包括小分子（如丙氨酸和半胱氨酸）。我们的数据表明，使用非还原四糖对手性 AA 的分离有效，可区分 21 种手性 AA，而无需使用金属离子。通过进一步加入铜离子，分离分辨率可提高至 1.64，与无金属分析中已实现的分离相比，额外提高了 52%。这些结果表明，使用四糖是通过 TIMS 分离 AA 对映体的有效策略。本研究中开发的方法可能为有效的 IMS 手性分析开辟新的策略。
