A direct and safe method for plutonium determination using total reflection X-ray fluorescence spectrometry

Abstract

A direct, simple and safe micro-analytical method for the determination of plutonium (Pu) using Total Reflection X-ray Fluorescence (TXRF) spectrometry is reported for the first time. The TXRF specimens were made by depositing sample solution aliquots containing 100–160 ng of Pu on quartz sample supports. The TXRF specimens of Pu, thus prepared after drying, were further isolated by dropcasting 10% collodion solution in amyl acetate on the sample spots. This novel methodology fixes Pu on TXRF supports, thus avoiding loose radioactive particles in TXRF specimens. These operations were carried out inside a fume hood. Since the analyte amount required for analysis was in ng levels, Pu particles fixed on the supports were in a non-dispersible form and the analysis was performed without touching the sample spot, there was no risk of Pu contamination, when these specimens were handled in the ambient atmosphere. The developed methodology showed the average precision of TXRF values as 3% (1σ, n = 3) and the average deviation of TXRF determined values from the expected values was 6% with a sample size of 100–160 ng of Pu and measurement time of 2000 seconds. The detection limit for Pu was 0.4 ng. The studies resulted in the development of a TXRF compositional characterization method for precious, hazardous and radioactive samples without putting the instrument inside a glove box and thus, avoiding complicated handling of the spectrometer inside the glove box as well as minimizing the sample amount, radiation dose and the radioactive waste generation.