Determination of isotopic ratios of uranium (U-235/-U238) for the characterization of reverse osmosis compared with conventional tap water treatment in order to determine the source of a water leak

Abstract

An analytical technique for the determination of the isotopic ratio of U-235/U-238 in waters by a classical technique based on a quadrupole ICP-MS has been implemented.
A high precision (RSD ≤ 0.3 %) has been obtained, which
is strictly necessary in these circumstances. The methodology
developed was validated and the results obtained confirmed a slight increase in the uranium isotopic ratio U-235/U-238 for the treated water using reverse osmosis with respect to conventionally treated water. This analytical methodology was applied to characterize different origins of treated water in the Barcelona Area in order to determine the origin of an important water leak. To the best of our knowledge, it is the first time that this isotopic application is used by a tap water distribution company to solve this kind of problem.