ARS | Publication request: Metal speciation of phosphorus derived from solid state spectroscopic analysis

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 1, 2010
Publication Date: August 8, 2011
Citation: Akinremi, O.O., Ajiboye, B., He, Z. 2011. Metal speciation of phosphorus derived from solid state spectroscopic analysis. In: He, Z., editor. Environmental Chemistry of Animal Manure. New York, NY: Nova Science Publishers. p. 301-324.

Technical Abstract: Significant improvements have been made in the last decade towards understanding metal species associated with manure P using XANES and solid-state 31P NMR techniques. Both solid-state techniques are particularly sensitive to inorganic forms of P associated with metals in manure samples. In unamended manure, the labile P fraction is commonly identified as calcium and magnesium phosphates. However, manures amended with chemicals like Al2(SO4)3 usually consist of aluminum phosphates, which have been clearly distinguished by both XANES and NMR spectra. Of the possible metal species of P in manure, Fe-P cannot be identified by solid state NMR due to the paramagnetic property of Fe(III). In contrast, a unique minor pre-edge feature is present in the P K-edge XANES spectra of Fe-P compounds, which could be especially useful for identifying Fe relevant P species in manure. Currently, both solid state spectroscopic techniques are mainly used to identify inorganic P species in manure. Recent literature on the reference spectra of different metal-organic P compounds (mainly phytate compounds) and technical improvement (i.e. P L2, 3-edge XANES) would facilitate characterizing metal speciation of manure P. Application of these solid state techniques and/or solution-based approaches in complementary and confirmatory manners could further increase confidence in the experimental results and provide a more complete spectrum of manure P characterization.