Variations in Δ 14C of humic substances in the Lake Biwa waters

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:259

Article; Proceedings Paper

Nagao, S. ; Kodama, H. ; Aramaki, T. ; Fujitake, N. ; Yonebayashi, K.

关键词: carbon-14;    humic substances;    lake water;    Lake Biwa;    delta C-13;   

DOI  :  10.1016/j.nimb.2007.01.199

来源: Elsevier

【 摘 要 】

Carbon isotopes (C-13 and C-14) were used to study the characteristics and origin of humic substances in water samples from Lake Biwa in Japan. Humic substances were isolated from surface lake waters in each season by the XAD extraction method and their carbon isotopic ratios were measured by accelerator mass spectrometry. The Delta C-14 values of Biwa humic and fulvic acids indicate that these substances consist mainly of pre-bomb C-14. There is a negative correlation between Delta C-14 and delta C-13 values for the Biwa fulvic acids. The fulvic acid consists of younger organic materials with lower delta C-13 value in January, but older organics with higher delta C-13 in April and October. The major part of fulvic acid may be supplied from soil solution and/or groundwater in the watershed and their contribution varies with season. (c) 2007 Elsevier B.V. All rights reserved.

【 授权许可】

Free