Development of pretreatment and analysis for environmental samples containing radiocaesium; Preliminary ToF-SIMS analysis of Cs isotope ratio in the microparticle

Tagomori, Hisaya*; Kawamura, Hidehisa*; Kusano, keiichi*; Dohi, Terumi   

To investigate their spatial distribution and physicochemical properties of the radiocaesium-bearing micro particles (CsMPs), an efficient methodology for determine and analysis them is required. Here we focused on CsMPs from litters as they may affect the radiocaesium cycling in forest ecosystem. In this study we developed a method to determine CsMPs (mostly 1-10 m sizes) from litters by combine digestion treatment and automatic particle analysis with FE-EPMA. In total it took up to 3 days for detecting one CsMP from huge amounts of mineral-like and metallic particles. In the ToF-SIMS analysis for Cs isotope ratios of CsMPs to understand their emission source as the next step, pretreatment for easily detecting micron-sized samples is needed. To solve this problem, FIB technique was used for Gallium marking formation around target sample. Preliminary Cs isotope ratios(133Cs, 134(Cs + Ba), 135Cs, 137(Cs + Ba)) and their distributions of CsMPs were determined by applying these approaches. We developed pretreatment for microscopy and ToF-SIMS analysis of CsMPs.