Volume 12, Issue 3 (May 1984)
A Rapid Method for Determining Triuranium Octoxide (U3O8) by Fluorometry
A rapid method for determining triuranium octoxide (U3O8) in geologic, biologic, and water samples by fluorometry is described. Release of total U3O8 from geologic samples was accomplished by fusing samples with lithium tetraborate at 1040°C (1904°F) and subsequently dissolving the molten sample in 1.6N nitric acid. U3O8 in biologic samples and in association with organic substances in water was liberated by oxidation with concentrated nitric acid. U3O8 in 1.6N nitric acid was complexed with trioctylphosphine oxide and extracted into cyclohexane. The recovery of 0.1-μg U3O8 in the presence of 100 to 500 μg each of potential interfering elements ranged from 99 to 105%. Results on reference samples corresponded well to the reported values. The new method proved to be more reproducible and efficient than the method that uses ethyl acetate extraction from a saturated aluminum nitrate solution for determining total U3O8 in geologic samples.