Development of an emanation method for the determination of radium3226 in ores using liquid scintillation

Abstract

A simple emanation method for the determination of radium-226 was developed. Radon was quantitatively removed from the de-emanation solution containing radium-226 when a total volume of carrier gas being equal to 15 times that of the de-emanation solution had been passed. The emanated radon was adsorbed on silica get at the temperature of an alcoholic slurry of liquid nitrogen. The silica gel was subsequently transferred at 0℃ to a toluene-based liquid scintiliator in a glass vial for counting. The counting efficiency of 3.5 opmPci ⁻¹ with a background count rate of 4 cpm was obtained. The detection limit was 1 Pci of radon. The recovery yield of the whole process was determined by analyzing a standard uranium ore, NBL 74 A, from the New Brunsvick Laboratory. An average recovery yield of 99.67± 0.54 per cent was obtained from ten separate experiments. Results of the analysis for the radium-226 content in 15 monazite samples were also reported.