TRACE ANALYSIS OF EXPLOSIVES BY THERMOSPRAY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY

A series of explosives were analyzed by thermospray high-performance liquid chromatography-mass spectrometry (TSP-HPLC-MS). Both positive and negative ion specta were acquired in thermospray and chemical ionization (filament-on) modes. The explosives proved most sensitive in the negative ion mode under chemical ionization conditions. The spectra for the explosives analyzed provided molecular weight information with few fragment ions. Detection limits from 200 pg for trinitrotoluene to 5 ng for ammonium picrate were obtained under full scan mass spectrometer conditions. TSP-HPLC-MS proved useful in separating and identifying components in commercial explosive mixtures without interferences from plasticizers as well as in detecting explosives from hand swabs with excellent sensitivity and specificity. The plasticizers primarily were detected in the positive ion mode while the explosives were most sensitive with negative ion detection.