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CPMAS 13 C NMR and IR spectra of spruce and pine litter and of the Klason lignin fraction at different stages of decomposition
Author(s) -
Zech Wolfgang,
Johansson MajBritt,
Haumaier Ludwig,
Malcolm Ronald L.
Publication year - 1987
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19871500413
Subject(s) - lignin , decomposition , chemistry , aromaticity , chemical composition , fraction (chemistry) , carbon 13 nmr , chemical structure , organic chemistry , nmr spectra database , chemical decomposition , molecule , spectral line , physics , astronomy
Fresh and decomposed spruce and pine litter and the Klason lignin fraction of spruce needles at different stages of decomposition were studied by CPMAS 13 C NMR and IR spectroscopy as well as by chemical methods. It was shown that decomposition of needles is accompanied by an increase in aliphatic substances and carboxyl group content; the amount of polysaccharides is reduced. It is assumed that stable aliphatic compounds like cutin and lipids of microbial origin will accumulate during litter decomposition and humification. Aromaticity is low and does not alter drastically. The NMR spectra of the Klason lignin fraction show pronounced peaks at 30, 55, 115, 130, 150 and 175 ppm. Obviously, this fraction contains appreciable amounts of aliphatic and carboxyl carbon besides the typical aromatic units of lignin. During decomposition aromaticity decreases whereas the relative amounts of aliphatic substances and carboxyl groups increase. This is probably due to splitting of aromatic ring structures and side chains. The findings agree with the results from chemical analyses.