Background Signal in Solid State 13C NMR Spectra of Soil Organic Matter (SOM)—Quantification and Minimization

2001 ◽  
Vol 20 (1-2) ◽  
pp. 74-84 ◽  
Author(s):  
Ronald J. Smernik ◽  
J.Malcolm Oades
Keyword(s):  
Organic Matter ◽  
Solid State ◽  
Soil Organic Matter ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Background Signal ◽  
Solid State 13C Nmr

Comparison of solid-state 13C NMR spectra of soil organic matter from an experimental burning site acquired at two field strengths

Soil Research ◽  
2008 ◽  
Vol 46 (2) ◽  
pp. 122 ◽  
Author(s):  
Ronald J. Smernik ◽  
Eileen Eckmeier ◽  
Michael W. I. Schmidt
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Organic Matter ◽  
Solid State ◽  
Soil Organic Matter ◽  
Nmr Spectra ◽  
Functional Group ◽  
13C Nmr Spectra ◽  
Nuclear Magnetic Resonance Spectra ◽  
Solid State 13C Nmr ◽  
Field Strengths

Solid-state 13C cross polarisation (CP) nuclear magnetic resonance spectra were acquired for 15 soil organic matter samples on 2 different spectrometers (200 MHz and 400 MHz). Distributions of broad functional group classes—carboxyl, aryl, O-alkyl, and alkyl—were determined by integration across broad chemical shift regions. The distributions derived from the 2 spectrometers were closely correlated (r2 = 0.77–0.93). Only slight biases were identified; carboxyl C contents were on average 8% lower and alkyl C contents 5% higher for spectra acquired on the 400 MHz spectrometer. These results indicate that valid 13C CP spectra can be acquired at field strengths up to 400 MHz, and that spectra acquired at different field strengths can be directly comparable.

scholarly journals Haloaldehyde Polymers LXII. High Resolution Solid State 13C NMR Spectra of Chloral and Bromal Polymers

1994 ◽  
Vol 26 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Koichi Hatada ◽  
Koichi Ute ◽  
Hiroshi Okuda ◽  
F W Hein Kruger ◽  
Otto Vogl
Keyword(s):  
Solid State ◽  
High Resolution ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Solid State 13C Nmr

High-resolution solid-state 13C NMR spectra of tetramethylammonium ions trapped in zeolites

1985 ◽  
Vol 113 (4) ◽  
pp. 368-371 ◽  
Author(s):  
Shigenobu Hayashi ◽  
Kunio Suzuki ◽  
Shigemitsu Shin ◽  
Kikuko Hayamizu ◽  
Osamu Yamamoto
Keyword(s):  
Solid State ◽  
High Resolution ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Solid State 13C Nmr

Quantitative aspects of solid-state 13C-NMR spectra of humic substances from soils of volcanic systems

Geoderma ◽  
1997 ◽  
Vol 80 (3-4) ◽  
pp. 327-338 ◽  
Author(s):  
P. Conte ◽  
A. Piccolo ◽  
B. Van Lagen ◽  
P. Buurman ◽  
P.A. de Jager
Keyword(s):  
Solid State ◽  
Humic Substances ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Solid State 13C Nmr

Virtual fractionation of charcoal from soil organic matter using solid state 13C NMR spectral editing

Soil Research ◽  
2000 ◽  
Vol 38 (3) ◽  
pp. 665 ◽  
Author(s):  
R. J. Smernik ◽  
J. O. Skjemstad ◽  
J. M. Oades
Keyword(s):  
Organic Matter ◽  
Solid State ◽  
Soil Organic Matter ◽  
13C Nmr ◽  
High Energy ◽  
Proton Spin ◽  
Inversion Recovery ◽  
Spectral Editing ◽  
Photo Oxidation ◽  
Solid State 13C Nmr

The solid state 13C NMR spectral editing technique proton spin relaxation editing (PSRE), which generates subspectra of components that have different proton relaxation rates and are spatially separated by at least 30–100 nm, was applied to hydrofluoric acid treated <53 m soil fractions from 8 Australian surface soils. Most of the aromatic signal was partitioned into the rapidly relaxing subspectrum, especially for the soils known to have high charcoal contents. However, the presence of other rapidly relaxing soil organic matter (SOM) components prevented a clean separation of charcoal from non-charcoal components. PSRE analysis was repeated after the samples had been treated with high energy ultraviolet photo-oxidation, which brings about the mineralisation of most SOM other than char. Excellent separation of the charcoal fraction by PSRE was achieved after photo-oxidation for 5 of the samples with the highest charcoal content. The rapidly relaxing subspectra for these samples also suggested that the charcoal present in soil contains significant carbonyl functionality, possibly as a result of in situ weathering. A new PSRE methodology is described, designed to best suit SOM samples. Data from inversion-recovery experiments were fitted to a model consisting of 2 components with different T1H relaxation rate constants, thus providing an objective best fit to the inversion-recovery data and avoiding the subjective judgements required in other PSRE methodologies.

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