Phosphorus (P) is an essential element for life on Earth, with an important and oftentimes unaccounted organic biogeochemical component. Current methods for the quantification of different organic P compounds in environmental samples (e.g., soils, sediments) are based on extraction techniques and often associated with incomplete P recovery or sample changes. In this study, we present a protocol for the quantification of different organic and inorganic P species in soils using synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy at the P L2,3-edge. Its accuracy and precision was evaluated by analyzing 40 standard mixtures composed of seven different inorganic and organic P compounds (with a mean of R2 = 0.85). In addition, we quantified the P species of two soils and two agro-industrial byproducts using P L2,3-edge XANES spectroscopy and the results were compared with those obtained by P K-edge XANES or 31P NMR spectroscopy. Using the P L2,3-edge, we identified different organic P species, including those not identified by the common P K-edge XANES. However, there is a consistent underestimation of organic polyphosphates. Overall, the application of P L2,3-edge XANES provides a higher level of information than by P K-edge XANES, although the ubiquitous use of this novel methodology is still limited to samples with a phosphorus content above 3 mg g-1.

中文翻译：

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通过P L2,3-边缘X射线吸收近边缘结构（XANES）光谱定量分析环境样品中不同无机和有机磷化合物的新方法。

磷（P）是地球上生命的必需元素，具有重要的且时常未说明的有机生物地球化学成分。当前定量环境样品（例如土壤，沉积物）中不同有机磷化合物的方法是基于提取技术的，并且通常与磷回收不完全或样品变化有关。在这项研究中，我们提出了在P L2,3-edge上使用基于同步加速器的X射线吸收近边缘结构（XANES）光谱对土壤中不同有机和无机P物种进行定量的协议。通过分析由7种不同的无机和有机P化合物组成的40种标准混合物（平均值为R2 = 0.85）来评估其准确性和精密度。此外，我们使用P L2量化了两种土壤和两种农工副产品的P物种，3边缘XANES光谱法，并将结果与​​通过P K边缘XANES或31P NMR光谱法获得的结果进行比较。使用P L2,3-edge，我们确定了不同的有机P种类，包括那些未被普通P K-edge XANES识别的种类。但是，有机多磷酸盐一直被低估。总的来说，尽管L2,3-edge XANES的应用提供了比P K-edge XANES更高的信息水平，但是这种新方法的普遍使用仍然限于磷含量高于3 mg g-1的样品。