泥炭フミン酸の構造に関する研究 (I)

NMRによる泥炭フミン酸の構造解析

抄録

The chemical structure of peat humic acids was estimated by means of nuclear magnetic resonance spectroscopic technique. The peat humic acid samples were prepared from extraction of Toyotomi moss peat, Ishikari reed peat and Kushiro reed peat with 1% sodium hydroxide, 3% sodium acetate and 1.8% sodium pyrophosphate aqueous solution. The NMR spectra were measured in deuteriodimethylsulfoxide with tetramethylsilane as an internal reference.
From the NMR data, it was found that the peat humic acids had lactone units in the molecules. The number of constitutive carbon, hydrogen and oxygen atoms contained in the various functional groups was obtained by elementary analyses and chemical analyses. By using these data, the structural parameters such as carbon aromaticity f_a, substitution parameter of aromatic system σ, alkyl substitution parameter to aromatic ring σ_ali and ratio of hydrogen to carbon in hypothetical unsubstituted aromatic material H_aru/C_ar, as summarized in Table 3 were calculated.
It was concluded that in the peat humic acids, the ratio of aromatic carbon atoms to all carbons is about 50% and the acids have mainly mono-ring systems with a few of naphthalene units in the aromatic constitution. The ratios of benzene to naphthalene unit are about 2-3: 1 for Ishikari reed peat and 4-6: 1 for Toyotomi moss peat and Kushiro reed peat.