Eu(III) binding abilities of dissolved humic substances isolated from deep groundwater in Horonobe area, Hokkaido, Japan

Terashima, Motoki  ; Seida, Yoshimi; Iwatsuki, Teruki  ; Iijima, Kazuki  ; Yoshikawa, Hideki; Yui, Mikazu; Nagao, Seiya*

Eu(III) binding abilities of dissolved humic substances (HSs), which were extracted from deep groundwater in the Horonobe Underground Research Center, Hokkaido, Japan, were investigated by fluorescence quenching technique. In the synthetic groundwater condition, the fluorescence quenching due to the binding with Eu(III) was not observed for the groundwater HSs, while that was observed for the Aldrich humic acid (HA). This result indicates that the binding ability of the groundwater HSs are different from that of Aldrich HA. Based on structural characteristics of the groundwater HSs, the differences in the binding ability are discussed.