A Novel Approach for the Quantification of Different Inorganic and Organic Phosphorus Compounds in Environmental Samples by P L_2,3-Edge X-ray Absorption Near-Edge Structure (XANES) Spectroscopy

Abstract

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 R 2 = 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.

Raman and XANES Spectroscopic Study of the Influence of Coordination Atomic and Molecular Environments in Biomimetic Composite Materials Integrated with Dental Tissue

“…This analytical method allows for characterisation of the speciation (coordination and redox state) of the main elements of mineralised hard tissues (here, Ca and P in calcium phosphates) as well as associated carbonate ions and organic molecules. The combination of XANES and synchrotron radiation, a source of high-intensity polarised X-rays in a given energy range, facilitates studies at the angstrom level, which opens up new horizons for understanding biomineralisation processes [28][29][30].…”

Unexpected Redispersion Effect of Au Nanoclusters for Enormous Enhancement of Electrocatalytic Stability and Activity

“…And the P atoms in AuCs/BP‐NG and AuNPs/BP‐NG all got electrons along with the peaks moving to lower energies. [ 27 ] It could be deduced that Au nanoclusters had strong chemical interaction with N and P atoms. The comparison of high‐resolution XPS results of N 1s (Figure 2d) among APTMS/BP‐NG, AuCs/BP‐NG, and AuNPs/BP‐NG showed that the peaks of AuCs/BP‐NG shifted to lower energy with obtaining electrons, with the noticeable shape change, but that peaks in AuNPs/BP‐NG had no obvious change.…”

Phosphorus Storage in Microalgae: STXM and XAS P K-Edge Investigation

“…To our knowledge this is the first STXM study performed using X-ray absorption spectroscopy at the P K-edge. For chemical specificity the P L 2,3 -edge is more sensitive, 16 but its low energy (133 eV) would require thin (100 nm) samples, with a risk of losing unbound P in the algae during sample preparation. Here, in contrast, complete algae could be measured, without any further preparation.…”