Transmission mode desorption electrospray ionization (TM-DESI) for simultaneous analysis of potential inorganic and organic components of radiological dispersion devices (RDDs).

Transmission mode desorption electrospray ionization (TM-DESI) coupled to an ion trap mass spectrometer capable of source collision-induced dissociation (CID) was used to completely analyze radiological dispersion device components. Source CID significantly enhanced the signal for metal ions by reducing adducts while eliminating chemical noise from background molecules through extensive fragmentation. Source CID spectra yielded reasonably accurate isotopic ratios for the metals studied. By switching the source CID on and off between scans, all major constituents in mixtures of simulated radionuclides and explosives were simultaneously observed. These results indicate that TM-DESI/ion trap technology could be a powerful on-site tool for nuclear forensics.