Multielement Monitoring for Dissolved and Acid-soluble Concentrations of Trace Metals in Surface Seawater along the Ferry Track between Osaka and Okinawa as Investigated by ICP-MS

Abstract

Multielement monitoring of the concentrations of trace metals dissolved in surface seawater collected at sampling stations along the ferry track between Osaka and Okinawa was performed by ICP-MS (inductively coupled plasma mass spectrometry). The surface seawater samples were collected by an automated sampling system for on-board sampling, which was installed on the bottom of a ferryboat. A part of each seawater sample was filtered with a membrane filter (pore size of 0.45 µm) immediately after sampling. Both filtered and non-filtered seawater samples were acidified to pH ca. 1 by adding conc. HNO₃, and were subjected to chelating resin preconcentration for the determination of trace metals by ICP-MS, where the concentrations of analyte metals in the filtered and non-filtered seawater samples were referred to as the dissolved and total concentrations, respectively. According to the thus-obtained results, it was found that most trace metals, especially below the 0.01 µg l^–1 as the dissolved and total concentrations, sensitively reflected the environmental pollution in the Osaka Bay and Seto Inland Sea area, as well as near to the Bungo Canal and the outlet of Kagoshima Bay.