Innovative methods for determination of ⁹⁰Sr and ¹³⁷Cs in soil samples based on effective radiochemical separation...

- Innovative methods were developed for direct ⁹⁰Sr and ¹³⁷Cs determination in soils by radiochemical separation and β-counting. Studies focused on: (1) the suitability of PEG to remove silica by coating, (2) the decontamination effect of Cs from ⁴⁰K, (3) iron elimination with Microthene-TOA column instead of oxalate complex, and (4) the effective separation of Y and Sr from Pb by a Microthene-TOA column which made the direct ⁹⁰Sr determination possible in less time with just one resin-column. The methods were validated by analysing the IAEA reference materials, showing good agreement with the recommended values. The methods were used to determine ⁹⁰Sr and ¹³⁷Cs in 21 soil samples. The obtained ⁹⁰Sr concentrations in the soils were in the range of 0.46-2.95 Bq kg^-1, while ¹³⁷Cs 1.24-35.5 Bq kg^-1. The yields of yttrium and caesium were 73.4 ± 8.0% and 79.0 ± 9.1%, respectively.