Analytical method of determination of ruthenium-106 in sea water.

寺 田喜久雄,西 村 かず よ,木 羽敏泰:金 沢大学理学部化学教室,金 沢市丸 の内1-1〒920 A simple and effective method for determining 106Ru in sea water is presented. After the sea water is heated with oxidants (potassium peroxodisulfate and potassium periodate) in potassium hy droxide solution, ruthenium tetraoxide is extracted into carbon tetrachloride from the aqueous solution adjusted to pH 4-6, and then back-extracted with a hydrochloric acid solution containing sodium hy drogen sulfite. Ruthenium metal is precipitated from the solution by adding magnesium powder, filtered, washed and dried under reduced pressure at room temperature. Chemical yield of ruthenium is measured by gravimetry, and the ƒÀ-activity is measured by a low-background ƒÀ-ray spectrometer, " Picobeta ". The over-all yield of ruthenium was 88-92% and the whole chemical procedure takes about 6 hours. The analytical results for 106Ru in sea water samples collected from several locations and depths of Japan Sea are presented.