Time-efficient method for the determination of Pb-210, Bi-210, and Po-210 activities in seawater using liquid scintillation spectrometry

A novel method has been developed for determining the natural decay series radionuclides (NDS), Pb-210, Bi-210, and Po-210, in seawater by way of state-of-the-art liquid scintillation spectrometry. For Pb-210 analysis, the method makes use of a Pb-212 yield tracer, prepared by ion exchange separation from aged Th(NO3)(4). Bi-210 recovery is determined using Bi-207 as the yield tracer, and Po-210 is determined using the conventional Po-208 yield tracer. The limits of detection for this method are 0.32, 0.34, and 0.004 mBq l(-1) for Pb-210, Bi- 210, and Po-210, respectively. The analysis can be completed within 10 days, as compared with up to one year for traditional methods. Results are presented for a preliminary study of Pb- 210, Bi-210, and Po-210 in the dissolved and particle-bound phases of Irish Sea water