NEUTRON ACTIVATION ANALYSIS OF HIGH-PURITY SELENIUM .V. SIMULTANEOUS DETERMINATION OF METALLIC IMPURITIES

Neutron activation analyses for Na, K, Cr, Fe, Co, Cu, Zn, Ga, Ag, Cd, La, W, Au and Tl in high-purity selenium in the p.p.m. and p.p.b. ranges were performed by irradiating 100-mg samples together with standards at a flux of 1013 n cm-2sec-1. The matrix activities from selenium, arsenic, germanium and bromine isotopes were separated by distillation in sulphuric acid-hydrobromic acid at 200-220°. The γ-emitting isotopes were measured simultaneously by γ-spectrometry with a Ge(Li) detector. The pure β-emitter 204Tl was precipitated as tetrathiourea thallium(I) perchlorate and thallium(I) chromate and counted with a G.M.-tube. © 1969.