Moutzouri Pinelopi, Simões de Almeida Bruno, Emsley Lyndon
Institut des Sciences et Ingéniere Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Institut des Sciences et Ingéniere Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
J Magn Reson. 2020 Dec;321:106856. doi: 10.1016/j.jmr.2020.106856. Epub 2020 Oct 22.
In H MAS spectra, the residual homogeneous broadening under MAS is due to a combination of higher-order shifts and splittings. We have recently shown how the two-dimensional anti-z-COSY experiment can be used for the removal of the splittings. However, this requires spectra with high resolution in the indirect dimension (t), leading to experiment times of hours. Here, we show how anti-z-COSY can be adapted to be combined with the two-dimensional one pulse (TOP) transformation which leads to significantly reduced experimental time while retaining the line narrowing effect. The experiment is demonstrated on a powdered sample of L-histidine monohydrochloride monohydrate, where the new TAZ-COSY sequence at 100 kHz MAS, yields between a factor 1.6 and 2.3 increase in resolution compared with the equivalent one-pulse experiment, in just 20 min. The same methodology is also adapted for the acquisition of liquid state H homodecoupled data, and an example is given for testosterone.
在高分辨魔角旋转（H MAS）谱中，魔角旋转下的残余均匀展宽是由高阶位移和分裂共同造成的。我们最近展示了二维反z-COSY实验如何用于消除分裂。然而，这需要间接维度（t）具有高分辨率的谱，导致实验时间长达数小时。在此，我们展示了反z-COSY如何进行调整以与二维单脉冲（TOP）变换相结合，这在保留谱线变窄效果的同时显著减少了实验时间。该实验在一水合L-组氨酸盐酸盐粉末样品上得到了验证，在100 kHz魔角旋转条件下，新的TAZ-COSY序列在仅20分钟内，与等效的单脉冲实验相比，分辨率提高了1.6至2.3倍。相同的方法也适用于获取液态氢同核去耦数据，并给出了睾酮的示例。
