Carbon-13 CP/MAS NMR and DR-FTIR spectroscopic studies of sugarcane distillery waste

1998 ◽  
Vol 78 (1) ◽  
pp. 227-236 ◽  
Author(s):  
M. B. Benke ◽  
A. R. Mermut ◽  
B. Chatson
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Organic Carbon ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
Distillery Waste ◽  
Angle Spinning ◽  
Cp Mas Nmr ◽  
C Nmr

The application of a sugarcane distillery waste known as vinasse to agricultural land has become a common practice in Brazil. The vinasse samples used in this study were collected from several sugarcane distilleries in Northeastern Brazil. These samples were fractionated into dissolved organic carbon (DOC) and particulate organic carbon (POC) fractions. Unfractionated and fractionated vinasse were studied using 13C cross-polarization and magic-angle spinning nuclear magnetic resonance (CP/MAS NMR) spectroscopy as well as diffuse reflectance Fourier-transform infrared (DR-FTIR) spectroscopy. Approximately 79 to 92% of the total unfractionated vinasse dry matter was in the form of DOC fraction. O-alkyl C (42–53% of the total C) and carboxyl C (12–25% of the total C) comprised a significant portion of the 13C NMR spectra of the DOC fraction. The presence of carbohydrates and COOH/COO− was suggested by the DR-FTIR as well. Both 13C NMR and DR-FTIR spectra of this fraction were generally similar to the spectra of the fulvic acid (FA) fraction of soil and sewage sludge. The spectra of DOC differed from the FA fraction in that they showed smaller amounts of aromatic C and had an absence of amide group (bands at 1650 cm−1 and 1540 cm−1). In the POC fraction, O-alkyl (17–52% of the total C) and alkyl C (15–41% of the total C) were the major contributors. The peaks at 62 ppm, 72 ppm, 84 ppm and 105 ppm in the O-alkyl region indicate the presence of cellulose and/or hemicellulose. The alkyl group was comprised mainly of long-chain structures. The total N content in this fraction is ~3–7 times as much as in the DOC fraction. The presence of amino acids in the POC fraction was suggested by both 13C NMR and DR-FTIR spectra. Key words:13C cross-polarization and magic-angle spinning nuclear magnetic resonance, dissolved organic carbon, Fourier-transform infrared, particulate organic carbon, vinasse

Carbon-Thirteen Cross-Polarization Magic Angle Spinning Nuclear Magnetic Resonance and Fourier Transform Infrared Studies of Thermally Modified Wood Exposed to Brown and Soft Rot Fungi

2003 ◽  
Vol 57 (3) ◽  
pp. 266-273 ◽  
Author(s):  
Hanne Sivonen ◽  
Mari Nuopponen ◽  
Sirkka L. Maunu ◽  
Franciska Sundholm ◽  
Tapani Vuorinen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Soft Rot ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
Heat Treated ◽  
Angle Spinning ◽  
Thermally Modified Wood ◽  
Modified Wood

Thermally modified wood has many technically interesting properties, such as increased dimensional stability, low equilibrium moisture content, and enhanced biological and weather resistance. This paper describes solid-state nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopic studies on the decay of heat-treated and untreated pine ( Pinus sylvestris) by brown ( Poria placenta) and soft rot fungi. Both techniques combined with multivariate data analysis proved to be powerful tools for the study of wood degradation by fungi. When untreated pine was exposed to brown or soft rot fungi, a drastic decay of the cell wall polysaccharides was observed. Brown rot fungus degraded mainly hemicelluloses while soft rot fungus attacked cellulose more extensively. The aromatic region of 13C cross-polarization magic angle spinning (CPMAS) NMR spectra revealed that the structure of lignin was also altered. New carboxylic structures were formed as a consequence of the decay. The increased biological resistance of pine wood heat-treated at >220 °C was observed in the 13C CPMAS NMR and IR spectra.

13C CP/MAS nuclear magnetic resonance of crystalline methylxylopyranosides

1985 ◽  
Vol 63 (1) ◽  
pp. 270-273 ◽  
Author(s):  
Michael G. Taylor ◽  
Robert H. Marchessault ◽  
Serge Perez ◽  
Peter J. Stephenson ◽  
Colin A. Fyfe
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
Asymmetric Unit ◽  
Angle Spinning ◽  
Detailed Nature ◽  
C Nmr

The 13C nmr spectra of solids, acquired using the Cross Polarization/Magic Angle Spinning (CP/MAS) technique, are very sensitive to the detailed nature of crystalline packing. These effects are illustrated in the CP/MAS spectra of the α and β anomers of methyl-D-xylopyranoside. In the spectrum of the α anomer, which crystallizes with two molecules per unit cell, individual spectra can be resolved for the two molecules in the asymmetric unit of this crystal.

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