Determination of polonium by dithizone extraction

Abstract

Polonium (210Po) was extracted with dithizonecarbon tetrachloride solution (5×10-4M)in 1N nitric acid, decomposed with conc. nitric acid, dried in a on a lanchet, and then α-activity was measured by a gas flow proportional counter or a Geiger-Müller counter, the counting efficiencies of which were 34.6±2.7% and 5.77±0.14% (95% C. L.), respectively. The percent extraction of polonium by one extraction was 99.4% and its separation from 100 mg copper, 20 mg mercury, 500 mg bismuth and 500 mg tellurium was possible by selecting suitable extracting condition. Lead and nickel did not interfere. Halogen ions showed disturbance in acid medium. The extraction from alkaline solution containing cyanide ions was possible. This method is suitable for control analysis of polonium in uranium refining process and the time required for an analysis is about 2 hours. The error of analysis is 10% (95% C. L.). © 1964, The Japan Society for Analytical Chemistry. All rights reserved.