Analytical Sciences

Abstract − Analytical Sciences, 29(2), 271 (2013).

Determination of 129I in Fukushima Soil Samples by ICP-MS with an Octopole Reaction System
Takeshi OHNO,* Yasuyuki MURAMATSU,* Chiaki TOYAMA,* Kazumi NAKANO,** Shinichiro KAKUTA,** and Hiroyuki MATSUZAKI***
*Department of Chemistry, Faculty of Science, Gakushuin University, Mejiro 1-5-1, Toshima, Tokyo 171-8588, Japan
**Agilent Technologies, Chemical Analysis, Japan Application Center, Takakura, Hachioji, Tokyo 192-8510, Japan
***Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
A method was developed for the determination of 129I in soil samples that uses an ICP-MS equipped with an octopole reaction system. Oxygen was used as the reaction gas for reducing the background intensity of m/z 129, principally by 129Xe+. The contribution of polyatomic ions, such as 127IH2+, could be effectively corrected for by assuming a production ratio (127IH2+/127I+ = 3 × 10−8). The measured 129I/127I ratios in a NIST standard solution and Fukushima soil samples are consistent with the expected value within the analytical error. This method provides a powerful tool for investigating radioiodine contamination in Fukushima and elsewhere.