Analysis of explosives using differential mobility spectrometry

Characterization of ions from eight explosives (2,4,6-trinitrotoluene, pentaerythritol tetranitrate, 2,4,6-trinitrophenol, 2,4-dinitrotoluene, erythritol tetranitrate, hexamethylene triperoxide diamine, 2,4,6-trinitrophenylmethylnitramine and 1,3,5-trinitro-perhydro-1,3,5-triazine) using differential mobility spectrometry (DMS) with ⁶³Ni as an ionization source was performed. Presented results of explosive analysis have been evaluated by use of special software tool which communicates with DMS in real time. This tool was developed for visualization, identification and comparison of measured data. Each explosive provides characteristic signal at a specific compensation voltage under a fixed dispersion field. Peaks in DMS spectra for these ions were confined to a range of compensation voltages between ?1.61 to +1.71 V at RF = 1060 V. We calculated specific alpha coefficients (α₂ and α₄) to obtain a nonlinear function of explosives, based on their DMS spectra. Dependence of mobility for measured explosives ions in electric field at E/N values between 0 to 120 Td were used to inspectional graphical differentiation of explosives.