Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Department of Electronic Science, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Department of Electronic Science, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
Anal Chim Acta. 2020 May 8;1110:109-114. doi: 10.1016/j.aca.2020.03.032. Epub 2020 Mar 17.
Resolution is an essential challenge in NMR spectroscopy. Narrow chemical shift range and extensive signal splittings due to scalar couplings often give rise to spectral congestion and even overlap in NMR spectra. Magnetic field strength is directly responsible for spectral resolution as higher magnetic field strength offers better signal dispersion. However, the process of further increasing magnetic field strength of NMR instruments is slow and expensive. Methodology aimed at resolution issue has long been developing. Here, we present a chemical shift upscaling method, in which chemical shifts are upscaled by a given factor while scalar couplings are unchanged. As a result, signal dispersion and hence the resolution are improved. Therefore, it is possible to separate multiplets which originally overlap with each other and to extract their integrals for quantitative analysis. Improved signal dispersion and the preservation of scalar couplings also facilitate multiplet analysis and signal assignment. Chemical shift upscaling offers a method for enhancing resolution limited by magnetic field strength.
分辨率是 NMR 光谱学中的一个基本挑战。由于标量耦合，窄的化学位移范围和广泛的信号分裂常常导致 NMR 光谱中谱带拥挤甚至重叠。磁场强度直接影响光谱分辨率，因为较强的磁场强度提供更好的信号色散。然而，进一步提高 NMR 仪器磁场强度的过程缓慢且昂贵。针对分辨率问题的方法学长期以来一直在发展。在这里，我们提出了一种化学位移扩展方法，其中化学位移按给定因子扩展，而标量耦合保持不变。结果，信号色散得到改善，分辨率也得到提高。因此，有可能分离原本相互重叠的多重峰，并提取它们的积分进行定量分析。改善的信号色散和标量耦合的保留也有助于多重峰分析和信号分配。化学位移扩展为增强受磁场强度限制的分辨率提供了一种方法。
