Identifying contraband nuclear material. View of a laboratory at the European Trans-Uranium Institute (ETUI), where the origin of contraband nuclear materials such as plutonium may be determined. In a glovebox, the sample is dissolved in a suitable solvent and diluted to a very low concentration. The sample is then placed in a glow discharge mass spectrometer (silver cylinder) which identifies impurities in the sample such as americium or gallium. The presence and quantity of such impurities acts as a 'signature' to the sample's country of origin, and may even identify the source production facility. The ETUI is in Karlsruhe, Germany.