Analysis procedure for halogen elements (bromine and iodine) in powder pellets using a sequential wavelength dispersive X-ray fluorescence spectrometry system at the Tono Geoscience Center, JAEA

Watanabe, Takahiro   ; Kida, Fukuka; Nara, Fumiko   ; Yamasaki, Shinichi*; Tsuchiya, Noriyoshi*

Total bromine and iodine concentrations in geological samples serve as valuable geochemical proxies for reconstructing past environmental changes, including relative sea-level changes and marine incursions into an inland area. These halogens have also been used in previous studies to identify past tsunami and storm surge deposits in geological records. Such information contributes to the evaluation of long-term geosphere stability, which is an essential aspect in the geological disposal of high-level radioactive waste. At the Tono Geoscience Center, a sequential wavelength dispersive X-ray fluorescence spectrometry system (WDXRF) has been installed for the major and trace element measurements. However, the application of WDXRF analyses to bromine and iodine has not been established. In this study, we developed analytical methods of total bromine and iodine contents using powdered pellets of standard reference materials. Additionally, evaluation tests of calibration curves were performed using the WDXRF. The validated method was then applied to sediment samples to examine its utility in determination of halogen concentrations.