Determination of 226Ra in urine and water samples and sequential separation of 228Ra and 90Sr in drinking water.

Among natural radionuclides, 226Ra and 228Ra intake can contribute considerably to radiological dose. Liquid scintillation counting offers a reliable and sensitive method for measurement in environmental (water) and biological (urine) matrices. While the determination of 226Ra in water is quite simple, its determination in urine requires a suitable radiochemical procedure. In both cases an indirect measurement of daughter 222Rn (with 218Po and 214Po) in secular equilibrium allows to determine 226Ra activity. Moreover, in presence of anthropogenic radionuclides, a sequential separation of 228Ra and 90Sr in water has been developed, isolating daughters 228Ac and 90Y in secular equilibrium in the same vial. [ABSTRACT FROM AUTHOR]