DETERMINATION OF WOOD COMPOSITION USING SOLID-STATE 13C NMR SPECTROSCOPY

In recent years, solid-state 13C NMR spectroscopy using the technique of cross-polarization (CP) and sample rotation at a magic angle (MAS) has been widely used in the analysis of plant materials, including wood. Knowledge of the composition, structure and behavior of wood components under various conditions is of great importance, since the properties of wood materials depend on this. In this work, differences in the composition of wood belonging to various tree species growing in central Russia (spruce, aspen, birch, oak, linden, pine, poplar and larch) were revealed using CP MAS 13C NMR spectroscopy. The assignment of various peaks in CP MAS 13C NMR spectra to the main components of wood was carried out. It was shown that cellulose is present in its amorphous and crystalline forms, the presence of lignin was unambiguously confirmed by the signals of aromatic carbon atoms, and hemicelluloses were detected by the signals from the carbon atoms of methyl groups of acetylxylose and L-rhamnose. According to the integral intensities, the total ratio of cellulose and hemicelluloses to lignin was determined: the largest amount of lignin was found in coniferous wood (spruce, larch and pine), and the smallest amount of lignin was detected in deciduous species (aspen, oak, linden, birch and poplar).

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CP MAS 13C NMR SPECTROSCOPY IN DETERMINATION OF SPECIFIC DIFFERENCES IN COMPOSITION OF WOOD

chemistry of plant raw material ◽

10.14258/jcprm.2021028790 ◽

2021 ◽

pp. 95-102

Author(s):

Sergey Gennad'yevich Kostryukov ◽

Pavel Sergeevich Petrov ◽

Yuliya Yurevna Masterova ◽

Tulfikar Djasim Idris ◽

Salohiddin Safarjonovich Hamdamov ◽

...

Keyword(s):

Nmr Spectroscopy ◽

13C Nmr ◽

13C Nmr Spectroscopy ◽

Magic Angle ◽

Plant Materials ◽

Sample Rotation ◽

Central Russia ◽

Coniferous Wood ◽

Main Components ◽

Cp Mas 13C Nmr

In recent years solid-state 13C NMR spectroscopy using the technique of cross-polarization (CP) and sample rotation at a magic angle (MAS) has been used in the analysis of plant materials, including wood. Knowledge of the composition, structure and behavior of wood components in different conditions is of great importance, since the properties of wood materials depend on this. In this work differences in the composition of various tree species wood in central Russia (birch, aspen, spruce, and larch) were revealed using CP MAS 13C NMR spectroscopy. Assignment of various peaks in CP MAS 13C NMR spectra with the main components of wood was carried out. It was shown that cellulose is presented in amorphous and crystalline forms, the presence of lignin is unambiguously confirmed by signals of aromatic carbon atoms, and hemicellulose is detected by signals from carbon atoms of methyl groups of acetylxylose and L-rhamnose. According to the integral intensities, the total proportion of cellulose and hemicellulose in relation to lignin was determined: the largest amount of lignin was found in coniferous wood (spruce, larch), and the smallest amount of lignin was detected in deciduous species (aspen and birch).

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SOLID-STATE 13C NMR SPECTROSCOPY IN POLYSACCHARIDE ANALYSIS

chemistry of plant raw material ◽

10.14258/jcprm.2020047610 ◽

2020 ◽

pp. 7-29

Author(s):

Sergey Gennad'yevich Kostryukov ◽

Pavel Sergeyevich Petrov

Keyword(s):

Solid State ◽

Nmr Spectroscopy ◽

13C Nmr ◽

Signal To Noise Ratio ◽

Human Life ◽

13C Nmr Spectroscopy ◽

Magic Angle ◽

Plant Materials ◽

Cp Mas 13C Nmr ◽

Solid State 13C Nmr

Polysaccharides are high molecular weight compounds represented by long linear and/or branched chains of monosaccharide residues linked by a glycosidic bond. Currently, there is a huge and rapidly-growing interest in the chemistry of polysaccharides due to their widespread use in various spheres of human life. The study of polysaccharide structure is a complex and non-trivial task, and in this area solid-state 13C NMR spectroscopy are widely applied in recent years. The review analyzes the possibilities of solid-state 13C NMR spectroscopy for the study of polysaccharides and natural objects containing polysaccharides. The evolution of 13C solid-state NMR spectroscopy methods is shown with the main focus on the usage of the cross-polarization (CP) technique based on rotating the sample under the magic angle (MAS), since in this case the spectra are obtained without artifacts signals and with the best signal-to-noise ratio and high resolution. The review focuses on cellulose as the most widespread polysaccharide, in addition, the applicability of CP-MAS 13C NMR spectroscopy for the study of other polysaccharides, as well as plant materials, is considered. The represented examples clearly show that CP-MAS 13C NMR spectroscopy is the most powerful experimental method that allows to obtain information on both the composition and structure of polysaccharides, as well as the composition of various plant materials. Moreover, the combination of available equipment and various techniques of solid-state 13C NMR experiment will contribute to the progress of further research in the chemistry of polysaccharides and their derivatives.

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