Determination of Tc-99 in coastal seawater collected in Fukuoka, Japan

Concentrations of Tc-99 were determined by inductively coupled plasma mass spectrometry (ICP-MS) on coastal seawater in the general environment in Japan. Technetium was enriched on iron hydroxide by repetitive co-precipitation method from a large volume of seawater and separated from impurities by solvent extraction and ion-exchange techniques. The concentrations of Tc-99 were 1.0 to 7.4 mu Bql(-1), which was one order of magnitude lower than the level reported on seawater from general environment by beta-ray counting. Concentrations of Cs-137 determined on the same seawater were 3.7 and 3.9 mEql(-1). The activity ratio of Tc-99/Cs-137 was calculated to be 2.7x10(-4). This ratio was very close to the value expected for fallout from nuclear tests.