Distributions and Geochemical Cycles of Platinum in Estuaries and Rivers of Tokyo and Otsuchi Areas, Japan
Distributions and Geochemical Cycles of Platinum in Estuaries and Rivers of Tokyo and Otsuchi Areas, Japan
Abstract:
Platinum (Pt) is now in use widely for various products, such as automobile catalysis and anticancer drugs, which might increase Pt concentrations in urban aquatic environments. However, the distributions and geochemical cycles of Pt in aquatic environments have not been clarified yet because of its low concentration. In this study, we revealed the distributions of Pt in the rivers and estuaries to discuss the influence of Pt emission from human activity on the oceanic environment.
Sub-picomolar level of Pt in seawater was determined using isotope-dilution Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after preconcentration by anion exchange resin. In Tama River around Tokyo, Pt concentrations increased rapidly at densely populated areas of Tokyo. On the other hand, in all the rural stations of Otsuchi River (Iwate Prefecture, Japan), Pt concentrations are lower than 0.015 pmol/L. Both at Tokyo and Otsuchi coastal areas, Pt concentrations in seawater are higher than those in open ocean. In Otsuchi areas, Pt concentrations are the highest (0.55 pmol/L) at mid salinity area (S=32.2) probably because Pt was released from the bottom sediments. In Tokyo Bay, Pt concentrations in estuarine waters ranged from 0.27 to 7.71 pmol/L. It was calculated that the discharge of Pt from Tokyo Bay estuarine area to open ocean is 0.24 % of global fluvial input of platinum. Compared with other areas like Otsuchi, there are strong anthropogenic sources in Tokyo estuary neighboring one of the mega-cities in the world.
Sub-picomolar level of Pt in seawater was determined using isotope-dilution Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after preconcentration by anion exchange resin. In Tama River around Tokyo, Pt concentrations increased rapidly at densely populated areas of Tokyo. On the other hand, in all the rural stations of Otsuchi River (Iwate Prefecture, Japan), Pt concentrations are lower than 0.015 pmol/L. Both at Tokyo and Otsuchi coastal areas, Pt concentrations in seawater are higher than those in open ocean. In Otsuchi areas, Pt concentrations are the highest (0.55 pmol/L) at mid salinity area (S=32.2) probably because Pt was released from the bottom sediments. In Tokyo Bay, Pt concentrations in estuarine waters ranged from 0.27 to 7.71 pmol/L. It was calculated that the discharge of Pt from Tokyo Bay estuarine area to open ocean is 0.24 % of global fluvial input of platinum. Compared with other areas like Otsuchi, there are strong anthropogenic sources in Tokyo estuary neighboring one of the mega-cities in the world.