Ethanol-soluble reduction products of peat humic acid have been characteriz-ed by means of
13C-and
1H-NMR spectroscopic technique.
The reduction of peat humic acid with sodium amalgam was carried out in 0.5 N sodium hydroxide aqueous solution at 100°C t for 4hr in a stream of nitrogen. And thus two parts of the ethanol-soluble humic acid and the ethanol-insoluble humic acid were obtained, as a result of a above reaction; the total yield of the ethanol-soluble humic acid namely fulvic acid in four reductive reactions was 43% based on the original peat humic acid. The
13C-NMR spectra of fulvic acid were measured in 26% deuteriodimethylformamide solution with tetramethylsilane as an internal reference.
By using the results of
13C-NMR spectra on a combination with
1H-NMR results, the structural parameters such as f
a, H
au/C
ar and σ were calculated.
It was concluded that the fulvic acid obtained by reduction of peat humic acid, the ratio of aromatic carbon atoms to all carbon in about 50%, and the acids have mainly mono-ring systems with a few of naphthalene units in the aromatic constitution.
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