Measurement of trace 129I in natural water with ozone reaction for effective separation of spectral interferences

• Published in: iScience 2024-12, Vol.27 (12), p.111138, Article 111138
• Main Authors: Zhu, Yanbei, Asakawa, Daiki
• Format: Article
• Language: English
• Subjects: Chemistry; Natural sciences; Physics
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.111138

Tandem quadrupole inductively coupled plasma mass spectrometry has the potential capability to measure 129I at extremely low concentration if spectral interferences from 129Xe and 127I1H2 can be eliminated effectively. Ozone was introduced as the reaction gas, resulting significantly improved reactions of (129I+→129I16O+) and (129I+→129I16O2+), and permitted the highly sensitive measurement of 129I+ as 129I16O+ and 129I16O2+, helping eliminate spectral interferences related to 129Xe+ and 127I1H2+. In isotopic ratio (129I/127I) analysis by measuring (129I+→129I16O2+)/(127I+→127I16O2+), a blank ratio of 6.7 × 10−10 can be realized for a solution of 500 μg/mL natural iodine, improved by one order of magnitude than the best performance previous reported. This technique contributes to the measurement of trace level 129I, a radionuclide of iodine attracting attentions as a geochemical tracer related to the development and civilian use of nuclear energy as well as a regulated radionuclide with guidance levels in drinking water established by the World Health Organization. [Display omitted] •Quantum chemical calculations showed potential merits of O3 for measuring 129I+•On-line generated ozone was used as the reaction gas for measuring of 129I+•The detection limit and the BEC of 129I were 0.062 pg/mL and 0.016 pg/mL•The 129I/127I ratio in 500 μg/mL natural iodine was observed to be 6.7 × 10−10 Natural sciences; Chemistry; Physics.