title: A study of Technegas employing X-ray photoelectron spectroscopy, scanning transmission electron microscopy and wet-chemical methods.
abstract: Scanning transmission electron microscopy (STEM), coupled with energy dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS) or radionuclear chemical methods, indicates that the active agent in Technegas is either polymeric TcO2[i.e. (TcO2)n] or (TcO2)n bound to a carbon nanoparticle. The particle size observed using STEM is in good agreement with other published results. XPS has also been used to investigate technetium residues remaining on spent crucibles. The chemical form of technetium in this residue is quite different to the form detected in the aerosol particles. We conclude that the small fraction that migrates into the crucible framework upon resistive heating is reduced to either metallic technetium or carbidic forms, with the remaining nuclide evaporating as (TcO2)n with or without carbon before complete reduction can occur.
authors.affiliation: School of Chemistry, University of New South Wales, Sydney, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Jackson
authors.forename: R J
authors.initials: RJ
authors.lastname: Baker
authors.forename: D G
authors.initials: DG
authors.lastname: McCulloch
authors.forename: D W
authors.initials: DW
authors.lastname: Mackey
authors.forename: H
authors.initials: H
authors.lastname: van der Wall
authors.forename: G D
authors.initials: GD
authors.lastname: Willett
mesh_terms: D002621:Chemistry / Q000379:methods; D004355:Drug Stability; D006108:Graphite; D017348:Microscopy, Electron, Scanning Transmission / Q000379:methods*; D013670:Sodium Pertechnetate Tc 99m; D013052:Spectrometry, X-Ray Emission / Q000379:methods*
chemical_list: C056708:Technegas; D006108:Graphite; D013670:Sodium Pertechnetate Tc 99m