Atmospheric pressure thermal desorption chemical ionization mass spectrometry for ultra-sensitive explosive detection

Illegal explosives are a threat to aviation, transport sector, critical infrastructure and generally to public safety. Their detection requires extremely sensitive instruments with efficient workflows that allow large throughput of items. In this study, we built a trace explosives detection instrument that requires minimal sample treatment and reaches ultra-low picogram level detection limits for many common explosives. The instrument is based on thermal desorption of filters, which allows analysis of liquid and solid phase samples, and subsequent selective atmospheric pressure chemical ionization and detection with a mass spectrometer. We performed experiments to scope the optimal ionization chemistry for the system and selected Br- as the reagent ion, and measured the limit of detection for 14 different explosives that were generally in the picogram range. Finally, we demonstrate the usability of the system by sampling air to a filter from a storage room known to contain explosives, from which we detect four different explosives.

Automated summary

Illegal explosives pose a threat to public safety, aviation, transportation, and critical infrastructure. Researchers have developed a trace explosives detection instrument with high sensitivity and efficient workflows. The instrument utilizes thermal desorption of filters for the analysis of liquid and solid phase samples, followed by selective atmospheric pressure chemical ionization and detection with a mass spectrometer. The experiments demonstrated that the system has low detection limits and can effectively detect various common explosives.