ARS | Publication request: Solid State Spectral Features of Metal Phytate Compounds

Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: September 6, 2006
Publication Date: November 12, 2006
Citation: He, Z., Honeycutt, C.W., Zhang, T., Pellechia, P.J., Caliebe, W.A. 2006. Solid State Spectral Features of Metal Phytate Compounds. Soil Science Society of America Annual Meeting. cd-rom.

Technical Abstract: Phytate (inositol hexaphosphoric acid, IP6) is a predominant form of organic phosphorus in animal manure, soil, and other organic substances. Whereas many studies have investigated the wet chemistry of IP6, there is little information on the characterization of solid metal IP6 compounds. This information is essential for further understanding and assessing the chemical behavior of IP6 in diverse soil-plant-water ecosystems. In this work, we characterized eight metal phytate compounds and investigated their structural features using Fourier transform infrared spectroscopy (FT-IR), solid state P-31 nuclear magnetic resonance (NMR) spectroscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Three different types of chemical structures of metal-phytate compounds were present based on FT-IR analysis. In solid state P-31 NMR spectra, Na, Ca, and Al phytates, as well as acidic K phytate, possessed distinguishable major isotropic chemical shift bands. Compared to inorganic phosphates, the spectra of metal phytates demonstrated strong spinning side bands. Similarly, differences were observed among the P K-edge XANES spectra of five metal phytate compounds. Significant differences can be observed in the intensity, position, and width of the white line at approximately 2153eV. This work demonstrated that the advanced spectroscopic technologies evaluated could be used to advance our knowledge of the fate of phytate, particularly as it interacts with metal species in the environment.