Identifying uranium particles using fission tracks and microsampling individual particles for analysis using thermal ionization mass spectrometry

Esaka, Fumitaka; Suzuki, Daisuke; Magara, Masaaki

Analytical Chemistry, 87(5), p.3107 - 3113, 2015/03

https://doi.org/10.1021/acs.analchem.5b00236

The analysis of uranium particles in environmental samples taken from nuclear facilities is a useful tool to unveil undeclared nuclear activities related to the production of nuclear weapons. An efficient method to analyze isotope ratios of individual uranium particles is thermal ionization mass spectrometry (TIMS) combined with a fission track technique. A drawback in the fission track-TIMS technique is so-called particle-mixing. Here, some uranium particles are measured as a single particle and an averaged isotope ratio is obtained, which may lead to misunderstanding conclusions for source identification. In the present study, micro-sampling under a scanning electron microscope has been added to the procedure of the fission track-TIMS technique. The analysis of a mixed sample containing uranium particles in SRM 950a and CRM U100 materials indicated that the problem of particle mixing was almost avoidable with the proposed technique.