The role of Cherenkov and liquid scintilation counting in evaluating the anion-exchange separation of210Pb−210Bi−210Po

Abstract

Using as eluent a sequence of 3M HCl, 12M HCl, and 8M HNO3, a mixture of210Pb,210Bi, and210Po may be clearly separated on a column of Dowex 1×2−100 anion exchange resin. A Cherenkov count in H2O and the variation in count rate with time confirm that the nuclides emerge in the order210Pb→210Bi→210Po. If 12M HCl is replaced by 1.5M H2SO4/2.3 M Na2SO4, a clean separation also results, but recovery of210Po becomes considerably more difficult. All three nuclides are readily detectable by liquid scintillation counting, with the efficiency for210Pb in the 60–70% range. The Cherenkov aqueous counting efficiency for210Bi is ∼14–15%.