Applications of switching reagent ions in proton transfer reaction mass spectrometric instruments for the improved selectivity of explosive compounds

- We present a method for the highly selective detection of explosives with a PTR-MS instrument.
- Ion-molecule reaction processes for TNT, TNB, PETN and RDX are investigated utilising O2+ and NO+ as reagent ions.
- Reagent ion switching time (H3O+, O2+ and NO+) is determined to be about 10 s.