@article{oai:nagoya.repo.nii.ac.jp:00012812,
 author = {城倉, 未来 and 今西, 健 and 中村, 俊夫 and 池田, 晃子 and 渡辺, 彰 and Jokura, Miku and Imanishi, Ken and Nakamura, Toshio and Ikeda, Akiko and Watanabe, Akira},
 journal = {名古屋大学加速器質量分析計業績報告書},
 month = {Mar},
 note = {Relationship between ^<14>C age and structural properties of humic substances in a brown forest soil was investigated using humic acids prepared from the lower layer soil of A2 horizon in a lnabu broad-leaved forest (Aichi, Japan). Humic acids were fractionated into 8 sub-fractions by fractional precipitation with 0.01 M NaOH-acetone solutions. Degree of humification estimated from two variables, A600/C (absorbance at 600 nm per mg CmL-1 in 0.1 M NaOH) and log(A400/A600) (the ratio of absorbance at 400 nm to that at 600 nm in logarhizumic scale), was greater in a fraction precipitated at a lower acetone mixing ratio. There were significant correlations between 14C age and the two variables expressing degree of humification. The slopes of regression lines between 14C age and A600/C and log(A400/A600) suggested the rate increasing degree of humification in the lnabu brown forest soil was much smaller than those in ando soils estimated in our previous study. Composition of C functional groups in the sub-fractions of lnabu humic acids were investigated using 13C cross polarization/magic angle spinning nuclear magnetic resonance spectroscopy. The proportions of aromatic C and alkyl C in total C showed positive and negative correlations, respectively, to 14C age, suggesting preferential loss of aliphatic components in humic acids in soil. Composition of polynuclear aromatic skeletons in humic acids was investigated by analyzing products upon ruthenium tetraoxide oxidation (RTO). Eight kinds of benzenepolycarboxylic acids (BPCAs) with two to six carboxy1 groups, derived possibly from polynuclear aromatic structures: naphthalene to coronene, and seven kinds of BPCAs with additional side chains were obtained. Yie1ds of BPCAs especially those with a larger number of carboxy1 groups corre1ated positively to ^<14>C age. The composition of BPCAs indicated that the aromatic components in humic acids with larger degrees of condensation were more refractory in soil., 第21回名古屋大学年代測定総合研究センターシンポジウム平成20(2008)年度報告},
 pages = {50--57},
 title = {褐色森林土における腐植物質の14C 年代と構造特性の関係},
 volume = {20},
 year = {2009}
}