Development of O-18 Isotope Ratio Measurements of Uranium Oxides and Surface Metal Oxides for Forensic Analysis
EMSL Project ID
33894
Abstract
Oxygen isotopic composition has proven to be useful in the forensic analysis of a variety of materials because variations in isotopic composition can reflect regional geographic differences or differences in material processing techniques. Therefore, it is desirable to investigate oxygen isotopic composition as a potential signature in nuclear forensic studies. However, efforts to characterized 18O ratios from strongly bound metal oxides with high precision and accuracy are complicated due to the difficulty in quantitatively liberating oxygen from uranium oxides via combustion techniques. Laser fluorination isotope ratio mass spectrometry (LF-IRMS) has been successful in the analysis of oxygen isotopes in olivine, zircon, and other minerals. It is proposed as a method of liberating oxygen from strongly bound metal oxides such as uranyl oxide and for oxide coated surfaces for analysis by high precision isotope ratio mass spectrometry. A laser fluorination interface for PNNL's dual inlet isotope ratio mass spectrometer will be developed to liberate and capture O2 from UO2 via laser-assisted reactions in the presence of BrF5. Initial testing will be done with silicon oxides. The laser fluorination and oxygen purification will be performed in buildings in the 300 Area. The design of the laser fluorination system, the cleaning of the silicon substrates and the oxygen isotope ratio measurements will be made in EMSL.
Project Details
Start Date
2009-04-08
End Date
2012-04-08
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members