The Estimation of Origin of Dissolved Organic Matter using the Three Dimensional Excitation Emission Matrix Spectroscopy in the Coastal Area

摘要

In order to elucidate the origin of dissolved organic matter (DOM) in the coastal area, we determined the concentration of nutrients, dissolved organic carbon (DOC), dissolved monosaccharide, and then measured the three dimensional excitation emission matrix spectrum. Sea water samples were collected on November 1999 and 6 June 2000 at the Gokasyo Bay in the Mie Prefecture. On 6 Juen 2000, the concentrations of nutrients were signficantly lower than they were on 17 November 1999. Therefore, phytopankton activity on 6 June 2000 might be higher than at on 17 November 1999. In contrast, the concentrations of DOC and monosaccharide on 6 June 2000 were higher than it was on 17 November 1999. From the results of the three dimensional excitation emission matrix spectrum, three types of fluorescence maximum peaks (Peak A; Ex./Em.=305-325/400-420 nm, Peak B; Ex./Em.=345-365/450-470 nm, Peak C; Ex. /Em.=275-280/345-355nm) were observed in seawater samples. It is belived that the source of peak A and peak B were terrestrial organic mater and that of peak C was biological particulated organic mater.