Performance Characteristics of Sequential Separation and Quantification of Lead-210 and Polonium-210 by Ion Exchange Chromatography and Nuclear Spectrometric Measurements
2006
El Afifi, E. M. | Borai, E. H.
A selective separation and quantitative determination procedure for ²¹⁰Pb and ²¹⁰Po in various environmental matrices from different sources such as IAEA-326 soil, phosphate rocks (PR), and phosphogypsum (PG) was developed. The tested samples were digested sequentially using concentrated mineral acids (HF, HNO₃) by a programmable high-pressure microwave digestion system. The sample solution was loaded onto a preconditioned ion exchange column (Sr-resin) for chromatographic separation. Polonium-210 was eluted by 6 M HNO₃ then spontaneously deposited onto polished silver discs to be measured using low-background alpha spectrometry. Lead-210 was sequentially eluted using 6 M HCl solution, precipitated as lead oxalate, dissolved in HNO₃ solution, and mixed with scintillation cocktail to be measured by liquid scintillation counting (LSC). Performance of the developed procedure was tested using a reference soil (IAEA-326), with recommended isotope values, that was used as a quality control to assess separation and quantification efficiency (recovery %). The minimum detectable activities of ²¹⁰Pb and ²¹⁰Po were found to be 24 and 0.28 Bq kg⁻¹ for the measurements using LSC and alpha spectrometry, respectively. The recoveries (%) of ²¹⁰Pb and ²¹⁰Po were found to be 80 and 60%, respectively. To test the validity of the proposed LSC method, a comparative study was performed by measuring ²¹⁰Pb activity concentration in test samples by nondestructive gamma-ray spectrometry.
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