Bromine and Iodine Analyses of Geological Samples by Wavelength Dispersive X-ray Fluorescence Spectrometry

Abstract

The bromine (Br) and iodine (I) content of geological samples can be used to understand various environmental phenomena such as past sea-level changes, geological uplift and subsidence, as well as marine incursion to the inland due to paleo tsunamis and storm surges. Wavelength dispersive X-ray fluorescence spectrometry (WDXRF) and energy dispersive X-ray fluorescence spectrometry (EDXRF) have been recognized as robust methods for the determination of the elemental composition of geological samples and a wide range of materials in research and technical fields, such as the chemical analysis of cultural properties, industrial and waste materials. However, determining Br and I content has been difficult due to the relatively low concentrations of these elements in geological samples and the limited number of reference materials for XRF analyses. Despite this, the polarizing EDXRF (Epsilon5, Malvern Panalytical) at Tohoku University produced sufficient results for determining the Br and I content of geological samples. In this study, we measured the Br and I content of possible standard materials and lake sediment samples using WDXRF at the Japan Atomic Energy Agency and polarizing EDXRF at Tohoku University. We compared the both results and confirmed that the WDXRF method can reliably determine Br and I content. In the future, we aim to develop a quantitative analysis of trace amounts of Br and I in solid samples through the identification and development of standard materials.