Pretreatment technique of environmental sample for radioactivity analysis using supercritical water reaction

Nagaoka, Mika  ; Fujita, Hiroki; Aida, Taku*; Smith, R.*

Radioactivity concentration in environmental sample such as leaf, seaweed has been measured through chemical separation with organic matter decomposition and extraction of target element. However, the usual chemical treatment could affect worker's health, chemical hood and surrounding environment by usage of chemical regent. On the other hand, supercritical water reaction could decompose organic matter without health and environmental hazard caused by the regent. Therefore, we have tried to apply the supercritical water reaction to radioactivity analysis of environmental samples. In this research, organic matter content and strontium concentration in environmental sample were compared with between before and after the reaction. The organic matters were highly decomposed with the water reaction at higher temperature and for longer reaction time. However the strontium was not extracted into solution after the reaction.