Determination of traces of ruthenium by neutron activation analysis using a polyethylene film

Acid solution of an inorganic chemical or seaweed ash is heated in a conical flask with oxidants, ruthenium ingredient is distilled and fixed on a polyethylene film, which is placed on the top of the flask. Many films were irradiated together in a thermal neutron flux, and after about a month γ-ray peak counts under the 497 keV peak of 103Ru were measured with a well-type NaI(Tl) or a Ge(Li) detector. In the chemicals of fifty one elements, compounds of four platinum metals were contamined with 2100-150 ppb Ru, and Ga, In, Tm, Tb, Yb: all trivalent elements contained 510-16 ppb Ru. The ruthenium content of all other chemicals were of ppb order or less. In these, Ga, In, Tm, and Yb were known as scintigram elements of cancer. In the ash of Porphyra tenera 2 ppb Ru was detected. (author)