Determination of Low-level Plutonium Isotopes (Pu, Pu) in Environmental Samples with High Uranium

In order to measure trace plutonium and its isotopes ratio (240Pu/239Pu) in environmental samples with a high uranium, an analytical method was developed using radiochemical separation for separation of plutonium from matrix and interfering elements including most of uranium and ICP-MS for measurement of plutonium isotopes. A novel measurement method was established for extensively removing the isobaric interference from uranium (238U1H and UH2)) and tailing of 238U, but significantly improving the measurement sensitivity of plutonium isotopes by employing NH3/He as collision/reaction cell gasses and MS/MS system in the triple quadrupole ICP-MS instrument. The results show that removal efficiency of uranium interference was improved by more than 15 times, and the sensitivity of plutonium isotopes was * Corresponding author at: Technical University of Denmark, Center for Nuclear Technologies, Risø Campus, Roskilde, Denmark E-mail address: xiho@dtu.dk (X.L. Hou). S. Xing and W.C. Zhang have same contribution to this paper.