抄録
The spectroscopic properties of fluorescent substances in the waters samples collected from the Kuji River system were investigated by three-dimensional excitation emission matrix (3-DEEM) spectroscopy without concentration. The river water samples were collected at seven sites in the Kuji River and at three sites in the tributary rivers. The 3-D EEM spectra were characterized by two broad excitaion/emission maxima at excitation (Ex.) 220±5/emission (Em.) 425±15nm and Ex. 325±10/Em. 430±15nm. The peak positions of excitation/emission maxima and peak height ratios in the water samples were in good agreement with those of soil fulvic acid extracted from the Ando soil, which is distributed in the Kuji River basin from the middle stream to the lower stream. The results suggest that fluorescent substances in the Kuji River waters mainly consist of fulvic-like substances which are supplied from the basin of the river system.
