[2A13-16] Nuclide Migration 1

[2A15] Molecular characterization of reactive deep underground dissolved organic matters for metal ion using high-resolution mass spectrometry

*Hayato Sato¹, Kanako Toda¹, Hikari Beppu², Yuki Amano², Kazuya Miyakawa², Takumi Saito¹ (1. UTokyo, 2. JAEA)

Keywords:High-resolution mass spectrometry, Radionuclides, Dissolved organic matters, Deep groundwater, Multivariate analysis

Molecular characterization of dissolved organic matter (DOM) components binding to metal ions was carried out for DOM in deep groundwater by relating the binding properties of DOM and metal ions obtained by fluorescence analysis to the molecular characteristics of DOM obtained from high-resolution mass spectrometry. In fluorescence analysis, quenching experiments with Eu³⁺ were carried out and the different fluorescent components were extracted, using multivariate analysis. In high-resolution mass spectrometry, mass spectra of DOM in deep groundwater were obtained using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and the chemical formula of organic molecules corresponding to the mass-to-charge ratios obtained was assigned. Both datasets were simultaneously evaluated to derive molecular characterization of organic compounds which bind to Eu³⁺.