Yanbei Zhu | Determination of calcium isotopes by ozone reaction ICP-QMS/QMS

Yanbei Zhu, National Institute of Advanced Industrial Science and Technology, Japan Title: Determination of calcium isotopes by ozone reaction ICP-QMS/QMS Abstract: In the measurement by inductively coupled plasma mass spectrometry (ICP-MS), the spectrum of Ca-40 is severerly interfered by that of Ar-40, which is the major isotope of the plasma gas. In the present work, calcium isotopes were determined by tandem quadrupole ICP-MS (i.e. ICP-QMS/QMS) with on-line generated ozone as the reaction gas. By shifting the reaction gas from oxygen to ozone, the relative yield of trioxide ion of Ca-40 was drastically improved from 1 % to 85 %. At the same time, the formation of trioxide ion of Ar-40 was negligible, which can be attributed to the property of its electronic structure. These characteristics of ozone reaction permited the highly sensitive measurement of Ca-40 at mass-shift mode (i.e. Ca+ → CaO3+) without apparent spectral interferences from Ar-40. The detailed mechanism of ozone reaction for generating trioxide ion of calcium was investigated via quantum chemistry calculations by using density functional theory. It was found that CaO3+ was formed by the consecutive reactions of Ca+ with O3, with CaO+ and CaO2+ as the intermediates. The present work showed that ozone reaction ICP-QMS/QMS permitted highly sensitive determination of the full set of calcium isotopes. Calium in multiple certified reference materials (CRMs) were determined with the present technique, covering various matrix such as coral, giant clam, dolomite, and limestone. The results based on each calcium isotope was identical to one another and agreed with the certified value of each CRM. Biography: Yanbei Zhu has completed his PhD in 2007 from Nagoya University, Japan. He is a chief senior researcher in National Institute of Advanced Industrial Science and Technology (AIST). He has published more than 120 papers in reputed journals and has been serving as an editorial board member of Analytical Science. Yanbei’s work is focused on quantitative elemental analysis based on ICP-MS related techniques, as well as the development of devices and instruments fascinating the sample pretreatment process and on-site analysis. #WCCE2026 #chemistry #chemistryconferences #catalysis #analyticalchemistry #organicchemistry #greenchemistry #nanotechnology #environmentalchemistry #inorganicchemistry #organometallics #materialscience #syntheticchemistry #biochemistry #greenchemistry #medicinalchemistry #chemicalresearch #chemicalengineering