ABSTRACT
In this article, an acetone-enhanced negative photoionization (AENP) source based on a 10. 6 eV vacuum ultraviolet ( VUV) lamp was developed and coupled to a home-made time-of-flight mass spectrometer for rapid detection of trace explosives. In the AENP source, acetone molecules absorbed 10. 6 eV photons and were ionized by single photon ionization to emit photoelectrons. The photoelectrons reacted with O2 , CO2 , etc. in the atmosphere to produce mainly CO-3 negative reactant ions. With this ionization source, common explosives, N-nitrobiz ( 2-hyolorolroxy ethyl )-amine dinitrate ( DINA ) , Tetryl, trinitrotoluene ( TNT ) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), could be detected sensitively, and the limit of detection of 2 pg ( TNT) with a linear range of 3 orders of magnitude was achieved. The simple structure, high sensitivity characteristics make the AENP source as a promising ionization source for mass spectrometry.