Executive summary Lead-210 (210Pb) is a beta particle emitting radionuclide in the uranium decay series and has therefore been an important part of the monitoring and research program of the eriss. eriss environmental radioactivity group of The radioanalytical laboratories have routinely used gamma and alpha spectrometric methods for determination, though 210Pb current techniques have some limitations. For gamma spectrometry, analysis can be performed immediately after sample preparation, but, the detection limits are quite high, thus this technique cannot be used for determination of radionuclide activity in environmental samples with low activity concentrations. In contrast, detection limits are very low for alpha spectrometric measurement but must be determined via its 210Pb direct daughter polonium-210, requiring complex separation chemistry and long ingrowth periods in order to achieve the low detection limits. Liquid scintillation counting (LSC) provides an alternative technique for 210Pb determination that allows measurement via the beta decay. Although LSC methods have some limitations, the detection limits approach those of alpha spectrometry and are approximately two orders of magnitude lower than gamma spectrometry. When compared to the alpha spectrometric method for determination, LSC can 210Pb significantly reduce the time taken for separation chemistry and therefore lead to faster analysis. This report provides a detailed description of a radiochemical separation and radiation eriss measurement technique developed in the radioanalytical laboratories for the determination of via LSC. Detection limits, uncertainty estimation and the 210Pb applicability of the method to various sample matrices are presented and discussed.
Executive summary Lead-210 (210Pb) is a beta particle emitting radionuclide in the uranium decay series and has therefore been an important part of the monitoring and research program of the environmental radioactivity group of eriss. The eriss radioanalytical laboratories have routinely used gamma and alpha spectrometric methods for 210Pb determination, though current techniques have some limitations. For gamma spectrometry, analysis can be performed immediately after sample preparation, but, the detection limits are quite high, thus this technique cannot be used for determination of radionuclide activity in environmental samples with low activity concentrations. In contrast, detection limits are very low for alpha spectrometric measurement but 210Pb must be determined via its direct daughter polonium-210, requiring complex separation chemistry and long ingrowth periods in order to achieve the low detection limits. Liquid scintillation counting (LSC) provides an alternative technique for 210Pb determination that allows measurement via the beta decay. Although LSC methods have some limitations, the detection limits approach those of alpha spectrometry and are approximately two orders of magnitude lower than gamma spectrometry. When compared to the alpha spectrometric method for 210Pb determination, LSC can significantly reduce the time taken for separation chemistry and therefore lead to faster analysis. This report provides a detailed description of a radiochemical separation and radiation measurement technique developed in the eriss radioanalytical laboratories for the determination of 210Pb via LSC. Detection limits, uncertainty estimation and the applicability of the method to various sample matrices are presented and discussed.
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