Characterization of Inorganic Explosive Salts using Particle Mapping Time-of-Flight Secondary Ion Mass Spectrometry
To help optimize ion mobility spectrometry (IMS) for the detection of inorganic explosives, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the thermal desorption behavior of ammonium nitrate (NH4NO3) and potassium perchlorate (KClO4) particles on surface. This was done by ToF-SIMS chemical imaging analysis to identify the change in the number of particles and their size before and after exposure to desorption temperatures of (150, 200, 250, 300, 350, and 400) °C for durations of (3, 6, 9, and 12) s. It was found that particles less than 7.2 µm in diameter contributed to more than 50 % of both the number and mass of the particles desorbed from the surface. Combining ToF-SIMS particle mapping with the aerosol collection experiment revealed that the technique could be used also to determine the optimum desorption temperatures of explosives particles; this was found to be approximately 200 °C and 300 °C for NH4NO3 and KClO4 particles, respectively. Although work remains to validate this number for KClO4, experiments using variable desorption-temperature IMS suggest the optimum temperature of NH4NO3 desorption to be approximately 200 °C.
Characterization of Inorganic Explosive Salts using Particle Mapping Time-of-Flight Secondary Ion Mass Spectrometry, Applied Surface Science, [online], https://doi.org/10.1002/sia.6077
(Accessed October 4, 2022)