Characterization of organic matter in a northern hardwood forest soil by 13C NMR spectroscopy and chemical methods

Geoderma ◽  
2003 ◽  
Vol 111 (1-2) ◽  
pp. 123-149 ◽  
Author(s):  
David A.N Ussiri ◽  
Chris E Johnson
Keyword(s):  
Organic Matter ◽  
Nmr Spectroscopy ◽  
Forest Soil ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Hardwood Forest ◽  
Northern Hardwood Forest ◽  
Chemical Methods ◽  
Northern Hardwood

scholarly journals CARBOXYMETHYLATION OF POLYSACCHARIDES – A COMPARATIVE STUDY

2020 ◽  
Vol 54 (9-10) ◽  
pp. 835-844
Author(s):  
GABRIEL LARS ◽  
ANTJE TIED ◽  
THOMAS HEINZE
Keyword(s):  
Nmr Spectroscopy ◽  
Caustic Soda ◽  
Comparative Study ◽  
13C Nmr ◽  
Reaction Medium ◽  
13C Nmr Spectroscopy ◽  
Water Soluble

The present study describes the heterogeneous carboxymethylation of xylan,α-1,3-glucan, glucomannan, pullulan, curdlan, galactoglucomannan, and agarose with sodium monochloracetate (SMCA) using iso-propanol as slurry medium in the presence of caustic soda. Using heteropolysaccharides for the carboxymethylation, higher DS values are obtained compared to the DS of homopolysaccharides. The influence of the amount caustic soda in the reaction medium is studied. The characterization of the products obtained is performed by means of 13C-NMR spectroscopy. Carboxymethylation transforms the investigated polysaccharides into water-soluble products.

Sulfur speciation, vertical distribution, and seasonal variation in a northern hardwood forest soil, U.S.A

1995 ◽  
Vol 25 (2) ◽  
pp. 234-243 ◽  
Author(s):  
B.R. Dhamala ◽  
M.J. Mitchell
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Forest Soil ◽  
Specific Activity ◽  
Soil Depth ◽  
Mineral Soil ◽  
Hardwood Forest ◽  
Northern Hardwood Forest ◽  
Northern Hardwood ◽  
Sulfur Speciation

Sulfur biogeochemistry of a northern hardwood forest soil in Bear Brook Watershed, Maine, was studied utilizing 35S in situ. The objectives of study were to characterize different S pools, their vertical distribution, and seasonal variation. Soil cores were used at the field and treated with 35SO42−. The distribution of total and C-bonded S followed a typical pattern of decreasing concentration with soil depth. More than 86% of total 35S added was retained by the soil. Most of the 35S activity was in the organic S pool (up to 73 and 20% of total 35S in C-bonded S and ester-sulfate forms, respectively) in both the forest floor and the mineral soil horizons. Ester sulfate increased with depth from 5.3 to 25.5% of total S. During the summer the relative importance of mineralization to immobilization decreased. Inorganic sulfate was the smallest S pool. However, higher specific activity and turnover rate of the inorganic 35SO42− pool than organic 35S pool indicated that S concentration and solution flux were more regulated by abiotic (adsorption and desorption) than biotic (mineralization and immobilization) processes.

Characterization of cellulose and cellulose derivatives in solution by high resolution 13C-NMR spectroscopy

1994 ◽  
Vol 19 (1) ◽  
pp. 29-78 ◽  
Author(s):  
Irene Nehls ◽  
Wolfgang Wagenknecht ◽  
Burkart Philipp ◽  
Dorothea Stscherbina
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Cellulose Derivatives
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