Development of Methodologies to Speciate Soil Nitrogen Using Solid-state NMR
EMSL Project ID
50456
Abstract
I am proposing to develop new methods for identifying nitrogen species utilizing solid-state NMR (ssNMR). These methods will not require extraction and can be used on whole soils (or minerals). However, this comes at the cost of resolution in the 1D NMR spectrum and typical ssNMR spectra of soils are most often interpreted by integrating whole regions of functional groups rather than individual species. By extending into a 2nd dimension more information can be gleaned, especially if we develop a new pulse sequence to edit that spectrum to reduce its complexity further. A second aspect will be to attempt to recover liquid like resolution by swelling with either D2O or DMSO-d6 and performing 14N NMR in a newly purchased gradient MAS probe (to mimic a Bruker HR-MAS?). In the solid-state these 14N NMR lines can be prohibitively broad and overlapping to the point of being indistinguishable. By swelling with solvent one can probe the hydrophilic (D2O) or the hydrophobic (DMSO) regions of the sample, thus restoring the averaging that gives rise to sharper NMR lines. Our goals are therefore:1) Develop and implement spin editing methods for multidimensional ssNMR experiments.
2) Investigate HR-MAS type experiments looking at 14N both directly or indirectly through the protons.
Project Details
Start Date
2018-10-11
End Date
2020-08-20
Status
Closed
Released Data Link
Team
Principal Investigator