Testing Method for On‐Site Measurement of Explosive Materials Contaminated on Travel Luggage Bag and Backpack Using Ion Mobility Spectrometry

Abstract

Testing method for the on-site detection of explosive materials contaminated on the travel luggage bag (TLB) and backpack (BP) surfaces was established using ion mobility spectrometry (IMS) and smear matrix. Trinitrotoluene and 1,3,5-trinitro-1,3,5-triazacyclohexane were used as model explosive materials. Two sampling methods of rolling (with a metal roller) and handrubbing were used, and stainless steel mesh was used as the smear matrix for collection of explosive material. Testing parts of the TLB and BP were selected in consideration of contaminant accumulation, physical contact, and sample collection. Explosive materials deposited on polytetrafluoroethylene (PTFE) sheet were transferred to the testing part, the explosive materials existing on the testing part were collected using the smear matrix, and then the collected explosive materials were analyzed using IMS. High signal-to-noise ratio over 10 was applied for the determination of the minimum initial explosive concentration (C min_PTFE ) to detect in IMS. The handrubbing method was much more efficient than the rolling method. The C min_PTFE values were different according to the testing parts. The C min_PTFE values of the TLB were higher than those of the BP. The experimental results were explained by difference in surface morphology of the testing areas. The testing method can be helpful to select the sampling parts and to collect the explosive materials for on-site security checks.