Radon in Water
Radon solubilities are special because we are dealing with a naturally radioactive isotope with a half-life of 3.8 days. The usual technique for determining the solubility of radon is to equilibrate it in a carrier gas like air or nitrogen with the liquid (or solution) it is to be dissolved in.
(1979). Radon in Water. IUPAC Solubility Data Series, 2, 227-229.