M. Wilson, K. Goh
Jun 1, 1983
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0
Influential Citations
12
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Journal
European Journal of Soil Science
Abstract
Summary The structure of the organic matter from the ‘A’ and ‘B’ horizons of Patua loam (New Zealand) which is soluble in sodium deuteroxide has been investigated by conventional 13C-nuclear magnetic resonance spectroscopy. Experiments using inverse gated 1H-decoupling and a variety of pulse delays and weighting functions for Fourier transformation are reported. Sufficient number of transients have been collected for quantitative estimates of the aromaticity of the extract. The results complement an earlier qualitative study on this soil (Wilson & Goh, 1977) and illustrate conditions under which conventional 13C-n.m.r. spectra of humic materials should be obtained. The sodium deuteroxide soluble material from Patua loam ‘A’ and ‘B’ horizons has an estimated aromaticity of 33%. Different carbon types are not well resolved. However, there appear to be seven distinct resonances in the carboxyl region of the A horizon of which at least six are not derived from inorganic sources. Together with results already recorded in the literature, the results illustrate the variability of humic acids isolated from different soils. The nature of this variability is discussed.