A rapid field extraction method for determination of radon-222 in natural waters by liquid scintillation counting

Fred W. Leaney,Andrew L. Herczeg

Limnol. Oceanogr. Methods 4:254-259 (2006) | DOI: 10.4319/lom.2006.4.254

ABSTRACT: A simple and robust method for determination of 222Rn in natural waters is described. A 1.3-L water sample is collected in a plastic (PET) water bottle and shaken with 20 mL mineral oil scintillant for 4 minutes. Radon preferentially migrates to the mineral oil, and the 222Rn activity is determined by counting 222Rn and the shortlived daughter products 214Po and 218Po using an ultra-low-level LS counter via α/β separation technique. The PET method achieves a detection limit of ~3 mBq L–1, making it an ideal method for analysis of surface water and groundwater samples.