High resolution characterization of organic phosphorus in soil extracts using 2D 1H-31P NMR correlation spectroscopy
2012 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 7, 3950-3956 p.Article in journal (Refereed) Published
Organic phosphorus (P) compounds represent a major component of soil P in many soils and are key sources of P for microbes and plants. Solution NMR (nuclear magnetic resonance spectroscopy) is a powerful technique for characterizing organic P species. However, <sup>31</sup>P NMR spectra are often complicated by overlapping peaks, which hampers identification and quantification of the numerous P species present in soils. Overlap is often exacerbated by the presence of paramagnetic metal ions, even if they are in complexes with EDTA following NaOH/EDTA extraction. By removing paramagnetic impurities using a new precipitation protocol, we achieved a dramatic improvement in spectral resolution. Furthermore, the obtained reduction in line widths enabled the use of multi-dimensional NMR methods to resolve overlapping <sup>31</sup>P signals. Using the new protocol on samples from two boreal humus soils with different Fe contents, two-dimensional <sup>1</sup>H-<sup>31</sup>P correlation spectra allowed unambiguous identification of a large number of P species based on their <sup>31</sup>P and <sup>1</sup>H chemical shifts and their characteristic coupling patterns, which would not have been possible using previous protocols. This approach can be used to identify organic P species in samples from both terrestrial and aquatic environments, increasing our understanding of organic P biogeochemistry.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2012. Vol. 46, no 7, 3950-3956 p.
Environmental Engineering Environmental Sciences related to Agriculture and Land-use
IdentifiersURN: urn:nbn:se:umu:diva-53091DOI: 10.1021/es204016hISI: 000302850400048PubMedID: 22394413OAI: oai:DiVA.org:umu-53091DiVA: diva2:509644