Solid-State Nuclear Magnetic Resonance (NMR) Methods Applied to the Study of Carbon Materials

2012 ◽  
pp. 85-170 ◽  
Author(s):  
Jair Freitas ◽  
Alfredo Cunha ◽  
Francisco Emmerich
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
Carbon Materials ◽  
Nmr Methods ◽  
Nuclear Magnetic

Comparison of nuclear magnetic resonance methods for the analysis of organic matter composition from soil density and particle fractions

2012 ◽  
Vol 9 (1) ◽  
pp. 97 ◽  
Author(s):  
Joyce S. Clemente ◽  
Edward G. Gregorich ◽  
André J. Simpson ◽  
Rajeev Kumar ◽  
Denis Courtier-Murias ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
1H Nmr ◽  
Solution State ◽  
Soil Fractions ◽  
13C Nuclear Magnetic Resonance ◽  
Nmr Methods ◽  
Solid State 13C Nmr ◽  
Nuclear Magnetic

Environmental contextThe association of specific organic matter (OM) compounds with clay mineral surfaces is believed to protect these compounds from degradation and thus result in long-term protection in soil. The molecular-level composition of soil OM associated with soil fractions was measured and compared using solid-state 13C nuclear magnetic resonance (NMR) and solution-state 1H NMR methods. Combining these methods allowed more detailed characterisation of OM associated with different soil fractions and will improve the understanding of OM dynamics in soil. AbstractOrganic matter (OM) associated with fine soil fractions is hypothesised to be protected from complete biodegradation by soil microbes. It is therefore important to understand the structure and stage of decomposition of OM associated with various soil fractions. Solid-state 13C nuclear magnetic resonance (NMR) spectroscopy has been used extensively to investigate the OM composition of soils and soil fractions. Solution-state 1H NMR spectroscopy has not been used as much but is an emerging tool for analysing soil OM because 1H NMR spectra are often better resolved and provide information that complements the structural information obtained from solid-state 13C NMR experiments. This study compares one-dimensional solution-state 1H NMR and solid-state 13C NMR methods for assessing the degradation and composition of OM in three different soils, and their light and clay-size fractions. The alkyl/O-alkyl degradation parameter was consistent across all NMR methods and showed that OM associated with clay-size fractions were at more advanced stages of degradation as compared to that in light density soil fractions. Solution-state 1H and diffusion edited (DE) 1H NMR results showed the presence of high concentrations of microbial-derived peptidoglycan and peptide side-chains in clay-sized fractions. Lignin was also identified in clay-sized fractions using solid-state 13C and solution-state 1H NMR techniques. The combination of solid-state 13C and solution-state 1H NMR methods provides a more detailed analysis of OM composition and thereby facilitates a better understanding of the fate and preservation of OM in soil.

scholarly journals Search for Axionlike Dark Matter Using Solid-State Nuclear Magnetic Resonance

2021 ◽  
Vol 126 (14) ◽  
Author(s):  
Deniz Aybas ◽  
Janos Adam ◽  
Emmy Blumenthal ◽  
Alexander V. Gramolin ◽  
Dorian Johnson ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dark Matter ◽  
Solid State ◽  
Magnetic Resonance ◽  
Nuclear Magnetic
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