Liquid-state, one-dimension ³¹P nuclear magnetic resonance spectroscopy (NMR) has greatly advanced our understanding of the composition of organic phosphorus in the environment. However, the correct assignment of signals is complicated by overlapping and shifting signals in different types of soils. We applied therefore for the first time diffusion-ordered spectroscopy (DOSY) to soil extracts, allowing us to separate phosphorus components in the second domain based on their translational diffusion coefficients. After successful application to a mixture of 14 model compounds, diffusion rates correlated closely with the molecular weight of the individual compound in aqueous solution (R² = 0.97). The method was then applied to NaOH/EDTA extracts of a grassland soil, of which paramagnetic contaminations were removed with sodium sulfide following high-velocity centrifugation (21 500g, 45 min) at 4 °C. Diffusion rates in soil extracts were again closely related to molecular weight (R² = 0.98), varying from 163.9 to 923.8 Da. However, our DOSY application failed for a forest soil with low organic phosphorus content. Overall, DOSY did help to clearly identify specific NMR signals like myo- and scyllo-inositol hexakisphosphate. It thus provides a more confident signal assignment than 1D ³¹P NMR, although currently the ubiquitous use of this novel methodology is still limited to soils with high organic phosphorus content.

中文翻译：

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扩散有序核磁共振波谱（DOSY-NMR）：一种用于鉴定土壤提取物中磷化合物的新型工具

液态一维³¹ P核磁共振波谱（NMR）大大提高了我们对环境中有机磷组成的了解。但是，信号的正确分配由于在不同类型的土壤中重叠和移动信号而变得很复杂。因此，我们首次将扩散有序光谱法（DOSY）应用于土壤提取物，从而使我们能够基于其平移扩散系数在第二域中分离磷成分。成功应用于14种模型化合物的混合物后，扩散速率与单个化合物在水溶液中的分子量密切相关（R ²= 0.97）。然后将该方法应用于草原土壤的NaOH / EDTA提取物，在4°C高速离心（21 500 g，45分钟）后，用硫化钠除去了顺磁污染物。土壤提取物中的扩散速率再次与分子量密切相关（R ² = 0.98），范围从163.9 Da到923.8 Da。但是，对于有机磷含量低的森林土壤，我们的DOSY应用程序失败了。总体而言，DOSY的确有助于清楚地识别特定像核磁共振信号肌-与鲨肌醇六磷酸。因此，与1D ³¹相比，它提供了更可靠的信号分配P NMR，尽管目前这种新方法的普遍使用仍然限于有机磷含量高的土壤。