The Analysis of Explosives by Tandem Mass Spectrometry

Data obtained via tandem mass spectrometry are reported for ions derived from several explosives and related compounds. Electron impact ionization, isobutane chemical ionization, and negative chemical ionization methods were used to form ions from each of the compounds studied. These compounds include o-, m-, and p-nitrotoluene; m-dinitrobenzene; 2,4-dinitrotoluene; 2,4,6-trinitrotoluene; 2,4-dinitrophenol; picric acid; 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX); 1,3,5,7-tetranitro-1,3,5,7-tetra-azacyclooctane (HMX); nitroglycerin; pentaerythritol tetranitrate (PETN); and ethylene glycol dinitrate (EGDN). For a given ionization method each class of compounds (that is, nitrobenzenes, heterocyclic nitramines, and nitrate esters) shows common decompositions. This promises to facilitate rapid screening for particular types of explosives by the neutral loss scanning procedure. Of the three ionization methods employed, electron impact ionization is least suitable for analysis of explosives by tandem mass spectrometry. Positive and negative chemical ionization methods, in contrast, tend to generate the types of ions most useful for analysis by tandem mass spectrometry.