scholarly journals Characterization of functional groups in estuarine dissolved organic matter by DNP‐enhanced 15N and 13C solid‐state NMR

ChemPhysChem ◽  
2021 ◽  
Author(s):  
Florian Venel ◽  
Hiroki Nagashima ◽  
Andrew G.M. Rankin ◽  
Christelle Anquetil ◽  
Vytautas Klimavicius ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solid State ◽  
Dissolved Organic Matter ◽  
Functional Groups ◽  
Solid State Nmr

Advanced Solid-State NMR Characterization of Marine Dissolved Organic Matter Isolated Using the Coupled Reverse Osmosis/Electrodialysis Method

2012 ◽  
Vol 46 (11) ◽  
pp. 5806-5814 ◽  
Author(s):  
Jingdong Mao ◽  
Xueqian Kong ◽  
Klaus Schmidt-Rohr ◽  
Joseph J. Pignatello ◽  
E. Michael Perdue
Keyword(s):  
Organic Matter ◽  
Solid State ◽  
Dissolved Organic Matter ◽  
Reverse Osmosis ◽  
Solid State Nmr ◽  
Nmr Characterization

scholarly journals Chemical characterization of water extractable organic matter from plants: A better understanding of soil dissolved organic matter sources and path in permafrost thawing regions 

2021 ◽  
Author(s):  
Alienor Allain ◽  
Marie Anne Alexis ◽  
Yannick Agnan ◽  
Guillaume Humbert ◽  
Edith Parlanti ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solid State ◽  
Dissolved Organic Matter ◽  
Vascular Plants ◽  
Inorganic Material ◽  
Bulk Sample ◽  
Permafrost Thawing ◽  
Extractable Organic Matter ◽  
Water Extractable

<p>In present permafrost thawing context, dissolved organic matter (DOM) is a key component that controls organic and inorganic material transfer from soil to hydrographic systems. In terrestrial environments, vegetation is the main source of DOM, before degradation by microorganisms. DOM stoichiometry, aromaticity, composition or quantity control its fate, and referential data characterizing the initial DOM originating from plant biomass leaching are scarce.</p><p>To better understand its dynamic, this study focuses on the characterization of water extractable organic matter (“WEOM”: a proxy of DOM) of main plant species belonging to different plant functional types typical of the subarctic region (lichen, willow, birch, and <em>Eriophorum</em>).</p><p>Dissolved organic carbon (C) and dissolved nitrogen (N) contents of WEOM samples were measured, as well as organic C and total N contents of ground plant leaf samples (“bulk” samples). C/N ratio of bulk samples and WEOM fractions were compared to evaluate the potential extractability of C and N. The composition of both WEOM and bulk samples were characterized through solid state <sup>13</sup>C Nuclear Magnetic Resonance (NMR) and compared. Absorbance and 3D fluorescence measurements were also performed on WEOM samples to characterize their optical properties.</p><p>WEOM is significantly more extractable in vascular plants compared to non-vascular ones. Moreover, N is more extractable than C in all lichen species and <em>Eriophorum</em>, whereas C is as extractable as N in <em>Salix </em>and <em>Betula pubescens</em> samples.<em> Betula nana</em> is the only species with C more extractable than N.</p><p>The solid state <sup>13</sup>C NMR spectra of bulk sample are very similar to the spectra of corresponding WEOM, except for <em>Eriophorum</em>. For this species, carbonyl C contributes to 5% of bulk sample spectrum, compared to 14% of the WEOM spectrum.</p><p>Based on absorbance measurements, optical index were calculated: E2/E3 is significantly higher for non-vascular plants, whereas E2/E4, E3/E4 and slope ratio (S<sub>R</sub>) do not show significant difference between plant functional types. In 3D fluorescence spectra, the contribution of “Protein-like” peak is lower for vascular plants compared to lichens, and is maximum for <em>Eriophorum</em>.</p><p>Our results highlighted the influence of plant species on the quantity and quality of produced DOM: WEOM production process is different between vegetation species due to the quality, especially hydrophobicity and extractability of bulk OM components. The high contribution of C-N bonds in WEOM of <em>Eriophorum </em>might be especially important for potential complexation between DOM and trace elements like cadmium (Nigam et al., 2000). Likewise, aromatic C observed only in vascular plant WEOM samples are known to bond have a good affinity with many elements like iron, vanadium and chromium (Gangloff et al., 2014). Under climate change, vegetation cover of the Arctic region is evolving with the moving of the treeline northward and a local increase of the proportion of shrubs (Berner et al., 2013). Accordingly, significant change of DOM composition are expected with potential influence on organic and inorganic material dynamics.</p><p>Berner et al., (2013). Glob. Chang. Biol. 19:3449-3462</p><p>Gangloff et al., (2014). Geochim. Cosmochim. Ac. 130:21-41  </p><p>Nigam et al., (2000). Chem. Speciation Bioavailability 12:125-132</p>

Chemical composition of dissolved organic matter from various sources as characterized by solid-state NMR

2015 ◽  
Vol 77 (4) ◽  
pp. 595-607 ◽  
Author(s):  
Zhigao Zhou ◽  
Bin Hua ◽  
Xiaoyan Cao ◽  
John Yang ◽  
Dan C. Olk ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Solid State ◽  
Dissolved Organic Matter ◽  
Solid State Nmr

Solid State NMR Characterization of Crosslinked Brominated Poly(Isobutylene-co-4-Methylstyrene)

1993 ◽  
Vol 66 (1) ◽  
pp. 109-120 ◽  
Author(s):  
R. R. Eckman ◽  
I. J. Gardner ◽  
H-C. Wang
Keyword(s):  
Solid State ◽  
Functional Groups ◽  
Solid State Nmr ◽  
Phenyl Ring ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Crosslinked Polymers ◽  
Nmr Characterization ◽  
Angle Spinning

Abstract The curing of brominated poly(isobutylene-co-4-methylstyrene) was studied using solid-state magic-angle-spinning NMR, a technique which is uniquely suited to investigate cured or crosslinked polymers. This brominated copolymer contains 4-bromomethylstyryl and 4-methylstyryl functional groups and was compression cured with pure ZnO. It was proposed that a precomplex is formed between zinc and the 4-bromomethylstyryl group, which generates a benzylic carbocationic intermediate. Crosslinking predominantly occurs by alkylation of the phenyl ring of another 4-bromomethylstyryl group by the benzylic intermediate. The ZnO brings the two bromides of these groups into proximity. The dependence of the cure chemistry on the concentration of 4-bromomethylstyryl functional groups was studied. Conversion of some 4-bromomethylstyryl groups to oxygenated species upon curing was also observed.

scholarly journals Use of Solid-State NMR Spectroscopy for the Characterization of Molecular Structure and Dynamics in Solid Polymer and Hybrid Electrolytes

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1207
Author(s):  
Gabrielle Foran ◽  
Nina Verdier ◽  
David Lepage ◽  
Cédric Malveau ◽  
Nicolas Dupré ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Pulse Sequence ◽  
Dynamic Properties ◽  
Double Resonance ◽  
Solid Polymer ◽  
Pulse Field ◽  
Solid State Nmr Spectroscopy

Solid-state NMR spectroscopy is an established experimental technique which is used for the characterization of structural and dynamic properties of materials in their native state. Many types of solid-state NMR experiments have been used to characterize both lithium-based and sodium-based solid polymer and polymer–ceramic hybrid electrolyte materials. This review describes several solid-state NMR experiments that are commonly employed in the analysis of these systems: pulse field gradient NMR, electrophoretic NMR, variable temperature T1 relaxation, T2 relaxation and linewidth analysis, exchange spectroscopy, cross polarization, Rotational Echo Double Resonance, and isotope enrichment. In this review, each technique is introduced with a short description of the pulse sequence, and examples of experiments that have been performed in real solid-state polymer and/or hybrid electrolyte systems are provided. The results and conclusions of these experiments are discussed to inform readers of the strengths and weaknesses of each technique when applied to polymer and hybrid electrolyte systems. It is anticipated that this review may be used to aid in the selection of solid-state NMR experiments for the analysis of these systems.

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