Characterization of Maya Crude Oil Maltenes and Asphaltenes in Terms of Structural Parameters Calculated from Nuclear Magnetic Resonance (NMR) Spectroscopy and Laser Desorption−Mass Spectroscopy (LD−MS)

2010 ◽  
Vol 24 (7) ◽  
pp. 3977-3989 ◽  
Author(s):  
T. J. Morgan ◽  
P. Alvarez-Rodriguez ◽  
A. George ◽  
A. A. Herod ◽  
R. Kandiyoti
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Crude Oil ◽  
Mass Spectroscopy ◽  
Structural Parameters ◽  
Laser Desorption ◽  
Nuclear Magnetic

Characterization of Natural Organic Matter by Nuclear Magnetic Resonance Spectroscopy

1997 ◽  
Author(s):  
Jerry A. Leenheer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Organic Matter ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Natural Organic Matter ◽  
Major Elements ◽  
Structure Information ◽  
Abundant Element ◽  
Nuclear Magnetic

Natural organic matter (NOM) is a major intermediate in the global carbon, nitrogen, sulfur, and phosphorus cycles. NOM is also the environmental matrix that frequently controls binding, transport, degradation, and toxicity of many organic and inorganic contaminants. Despite its importance, NOM is poorly understood at the structural chemistry level because of its molecular complexity and heterogeniety. Nuclear magnetic resonance (NMR) spectroscopy is one of the most useful spectrometric methods used to investigate NOM structure because qualitative and quantitative organic structure information for certain organic elements can be generated by NMR for NOM in both the solution and solid states under nondegradative conditions. However, NMR spectroscopy is not as sensitive as infrared or ultraviolet-visible spectroscopy; it is not at present applicable to organic oxygen and sulfur, and quantification of NMR spectra is difficult under certain conditions. The purpose of this overview is to present briefly the “state of the art” of NMR characterization of NOM, and to suggest future directions for NMR research into NOM. More comprehensive texts concerning the practice of NMR spectroscopy and its application to NOM in various environments have been produced by Wilson and by Wershaw and Mikita. Carbon, hydrogen, and oxygen are the major elements of NOM; together they comprise about 90% of the mass. The minor elements that constitute the remainder are nitrogen, sulfur, phosphorus, and trace amounts of the various halogen elements. With the exception of coal, in which carbon is the most abundant element, the order of relative abundance in NOM on an atomic basis is H > C > O > N > S > P = halogens. The optimum NMR-active nuclei for these elements are 1H, 13C, 17O, 15N, 33S, 31P, and 19F. The natural abundances and receptivities of these nuclei relative to 1H are given in Table 12.1. Quadrupolar effects for 17O, 33S, and halogen elements other than 19F lead to line broadening that greatly limits resolution in NMR studies of these elements in NOM.

Structural Characterization of Ca2+-ATPase-Bound Phospholamban in Lipid Bilayers by Solid-State Nuclear Magnetic Resonance (NMR) Spectroscopy†,‡

Biochemistry ◽  
2008 ◽  
Vol 47 (15) ◽  
pp. 4369-4376 ◽  
Author(s):  
Karsten Seidel ◽  
Ovidiu C. Andronesi ◽  
Joachim Krebs ◽  
Christian Griesinger ◽  
Howard S. Young ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Lipid Bilayers ◽  
Structural Characterization ◽  
Nuclear Magnetic

scholarly journals Qualitative and Quantitative Analysis of Heavy Crude Oil Samples and Their SARA Fractions with 13C Nuclear Magnetic Resonance

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 995
Author(s):  
Ilfat Rakhmatullin ◽  
Sergey Efimov ◽  
Vladimir Tyurin ◽  
Marat Gafurov ◽  
Ameen Al-Muntaser ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Crude Oil ◽  
Functional Groups ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Sara Fractions ◽  
Nuclear Magnetic

Nuclear magnetic resonance (NMR) approaches have unique advantages in the analysis of crude oil because they are non-destructive and provide information on chemical functional groups. Nevertheless, the correctness and effectiveness of NMR techniques for determining saturates, aromatics, resins, and asphaltenes (SARA analysis) without oil fractioning are still not clear. In this work we compared the measurements and analysis of high-resolution 13C NMR spectra in B0 ≈ 16.5 T (NMR frequency of 175 MHz) with the results of SARA fractioning for four various heavy oil samples with viscosities ranging from 100 to 50,000 mPa·s. The presence of all major hydrocarbon components both in crude oil and in each of its fractions was established quantitatively using NMR spectroscopy. Contribution of SARA fractions in the aliphatic (10–60 ppm) and aromatic (110–160 ppm) areas of the 13C NMR spectra were identified. Quantitative fractions of aromatic molecules and oil functional groups were determined. Aromaticity factor and the mean length of the hydrocarbon chain were estimated. The obtained results show the feasibility of 13C NMR spectroscopy for the express analysis of oil from physical properties to the composition of functional groups to follow oil treatment processes.

Characterization of Crude Oil Products Using Data Fusion of Process Raman, Infrared, and Nuclear Magnetic Resonance (NMR) Spectra

2011 ◽  
Vol 65 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Thomas I. Dearing ◽  
Wesley J. Thompson ◽  
Carl E. Rechsteiner ◽  
Brian J. Marquardt
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Data Fusion ◽  
Crude Oil ◽  
Nmr Spectra ◽  
Oil Products ◽  
Using Data ◽  
Nuclear Magnetic

Isolation and characterization of antiplasmodial constituents from the marine sponge Coscinoderma sp.

2019 ◽  
Vol 74 (11-12) ◽  
pp. 313-318
Author(s):  
Huijeong Jeong ◽  
Abdul Latif ◽  
Chang-Suk Kong ◽  
Youngwan Seo ◽  
Yeon-Ju Lee ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Plasmodium Falciparum ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Marine Sponge ◽  
Antiplasmodial Activity ◽  
Isolation And Characterization ◽  
C Nmr ◽  
Nuclear Magnetic

Abstract Six known compounds, namely two halisulfates 1 and 2 and four epidioxy sterols 3–6, were isolated from the marine sponge Coscinoderma sp. The structures of these compounds were confirmed by nuclear magnetic resonance (1H and 13C NMR) spectroscopy, and their antiplasmodial activities were determined against the chloroquine-resistant Dd2 strain of Plasmodium falciparum. The epidioxy steroids 3–6 all showed moderate to weak antiplasmodial activity, with IC50 values of 2.7 μM for (24S)-5α,8α-epidioxy-24-methylcholesta-6-en-3β-ol (3), 11.6 μM for 5α,8α-epidioxycholesta-6,24(28)-dien-3β-o1 (4), 2.33 μM for 5α,8α-epidioxy-24-methylcholesta-6,9(11)-24(28)-trien-3β-ol (5), and between 12 and 24 μM for 5α,8α-epidioxycholesta-6-en-3β-ol (6). In contrast, halisulfate 2 (1) was inactive, and halisulfate 1 (2) had an of IC50 value of about 24 μM.

scholarly journals Molecular characterization of ombrotrophic peats by humeomics

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Giovanni Vinci ◽  
Pierluigi Mazzei ◽  
Marios Drosos ◽  
Claudio Zaccone ◽  
Alessandro Piccolo
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magic Angle Spinning ◽  
Molecular Composition ◽  
Proton Nuclear Magnetic Resonance ◽  
Magic Angle ◽  
Binding Strength ◽  
Nuclear Magnetic

Abstract Background An insight into the molecular composition of ombrotrophic peats of different geographical origin and collected at different depths was achieved by the humeomics method. The humeomic fractionation allowed the separation of molecular components in either organic solvents or water on the basis of their progressive binding strength to the humic matrix. The solubilized matter in fractions was analyzed by gas chromatography–mass spectrometry (GC–MS) or by proton nuclear magnetic resonance (1H NMR) spectroscopy, while the residues depleted of the extracted material were observed by 13C cross-polarization magic-angle-spinning nuclear magnetic resonance (13C-CPMAS-NMR) spectroscopy. Results The analytical characterization of fractions and residues differentiated peats not only on the basis of the different classes of extracted molecules, but also on their binding strength to the complex peat matrix. Aromatic, lipidic, and sugar compounds were the most representative molecular classes extracted in the humeomic fractions and their abundance varied with depth. The distribution and abundance of extracted compounds provided an indication of the extent of organic matter accumulation in peat. The NMR spectra of solid residues supported the interpretation of the characteristics of the various extracts. Conclusions Our findings proved that the humeomic approach allows to provide important information on both the molecular composition of peats and its variation with depth.

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