Variation of Δ 14 C and δ 13 C Values of Dissolved Humic and Fulvic Acids in the Tokachi River System in Northern Japan

Characteristics of dissolved humic and fulvic acids in river waters were studied during 2003–2005 at 4 sites located in the headwaters and in the upper and lower Tokachi River, including a lowland tributary site. Fulvic acids from the headwaters to downstream areas have similar elemental composition and 13 C-NMR spectra. Humic acids have similar characteristics in the Tokachi River system. In contrast, δ 13 C and Δ 14 C values exhibit a decreasing trend from the upper to the lower and tributary sites, although the headwater site has heavier δ 13 C and lower Δ 14 C values than the upper site. Fulvic acids had similar δ 13 C values from the upper to lower sites, but 123′ higher in Δ 14 C than those of humic acids on average. The δ 13 C and Δ 14 C values exhibited differences in downward variation for humic and fulvic acids. In the Tokachi River system, these results suggest that differences in transport pathways and residence times of humic and fulvic acids reflect differences in the δ 13 C and Δ 14 C values in a single river basin

Dissolved organic carbon · Drainage basin · Fertilizer · Fulvic acid · Geography · Humic acid · Tributary · Chemistry · Geology and Paleoclimatology Research · Isotope Analysis in Ecology · Marine and coastal ecosystems · Environmental Chemistry · Geology

• AMS Radiocarbon Dating of Ancient Oriental Iron Artifacts at Nagoya University

  Open Access•Toshio Nakamura, Masahiro Hirasawa et al.•Radiocarbon•1995

  Add to list

• Discussion Reporting of 14 C Data

  Open Access•Minze Stuiver, Henry A Polach•Radiocarbon•1977

  Add to list