Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
Anal Chem. 2022 Sep 20;94(37):12757-12761. doi: 10.1021/acs.analchem.2c02411. Epub 2022 Sep 7.
Most interesting problems in chemistry, biology, and pharmacy involve mixtures. However, analysis of such mixtures by NMR remains a challenge, often requiring the mixture components to be physically separated before analysis. A variety of methods have been proposed that exploit species-specific properties such as diffusion and relaxation to distinguish between the signals of different components in a mixture without the need for laborious separation. However, these methods can struggle to distinguish between components when signals overlap. Here, we exploit the relaxation properties of selected nuclei to distinguish between different components of a mixture while using pure shift methods to increase spectral resolution by up to an order of magnitude, greatly reducing signal overlap. The advantages of the new method are demonstrated in a mixture of d-xylose and l-arabinose, distinguishing unambiguously between the five major species present.
化学、生物学和药学中最有趣的问题涉及混合物。然而，通过 NMR 对这些混合物进行分析仍然是一个挑战，通常需要在分析之前将混合物成分物理分离。已经提出了各种利用物种特异性性质（如扩散和弛豫）来区分混合物中不同成分信号而无需繁琐分离的方法。然而，当信号重叠时，这些方法可能难以区分成分。在这里，我们利用选定核的弛豫性质来区分混合物的不同成分，同时使用纯位移方法将光谱分辨率提高一个数量级，从而大大减少信号重叠。该新方法的优点在 d-木糖和 l-阿拉伯糖的混合物中得到了证明，能够明确地区分存在的五个主要物种。
