Determination of 210Pb by measurement of 210Pb and its progenies using a liquid scintillation counter

Lead-210 is a useful tracer in environmental studies for a wide range of applications, particularly in atmospheric research and geochronology. Liquid scintillation counting (LSC) is a commonly used measurement method for Pb-210 analysis. In the present work, to increase detection efficiency, an improved LSC technique for Pb-210 determination was developed. After adding lead carrier, samples were decomposed with mineral acid in closed digestion vessels. Using extraction chromatography with Sr resin, Pb-210 was selectively separated and precipitated as lead oxalate. Following re-dissolution, the solution was mixed with a scintillation cocktail and measured by a liquid scintillation counter. In this study, all the spectral regions with peaks of Pb-210, Bi-210, and Po-210 were used to calculate the activity of Pb-210; this is in contrast to the existing method, which divides the spectra into three regions according to energy level, and then selects only the Pb-210 region. The method in this study also addresses a procedure for correcting blank values to account for Pb-210 activity in the Pb2+ carrier. This measurement technique, using the spectral regions of Pb-210, Bi-210, and Po-210, exhibited more than twice the detection efficiency of the conventional method using only the Pb-210 spectrum region. This measurement technique is expected to be a useful method for Pb-210 analysis of environmental samples that show low activity, and when sample amounts are limited.