Standoff trace explosives vapor detection at meter distances

Megan K Nims; Elizabeth H Denis; Garret L Hart; Nancy M Escobedo; Shannon E Murphy; R Shane Addleman; Igor Novosselov; Robert G Ewing

doi:10.1016/j.talanta.2023.125562

Standoff trace explosives vapor detection at meter distances

Talanta. 2024 Apr 1:270:125562. doi: 10.1016/j.talanta.2023.125562. Epub 2023 Dec 16.

Authors

Megan K Nims¹, Elizabeth H Denis², Garret L Hart³, Nancy M Escobedo³, Shannon E Murphy³, R Shane Addleman³, Igor Novosselov⁴, Robert G Ewing⁵

Affiliations

¹ Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSIN P7-50, Richland, WA 99352, USA. Electronic address: megan.nims@pnnl.gov.
² Pacific Northwest National Laboratory, 1100 Dexter Avenue North, Suite 500, Seattle, WA 98109, USA. Electronic address: elizabeth.denis@pnnl.gov.
³ Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSIN P7-50, Richland, WA 99352, USA.
⁴ Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE Seattle, WA, 98195, USA.
⁵ Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSIN P7-50, Richland, WA 99352, USA. Electronic address: robert.ewing@pnnl.gov.

PMID: 38159354
DOI: 10.1016/j.talanta.2023.125562

Abstract

Vapor detection is a noncontact sampling method, which is a less invasive means of explosives screening than physical swiping. Explosive vapor detection is a challenge due to the low levels of vapors available for detection. This study demonstrates that the parts-per-quadrillion sensitivity of atmospheric flow tube-mass spectrometry (AFT-MS) combined with a high-volume air sampler enables standoff detection of trace explosives vapor at distances of centimeters to meters. Standoff detection of explosives vapor was possible both upstream and downstream of the vapor source relative to room air currents. RDX vapor from a saturated source was detected at up to 2.5 m. Vapors from RDX residue and nitroglycerin residue were detected at distances up to 0.5 m. The sampling can be optimized by accounting for air movement in the room or environment, which could further extend standoff detection distances. Using AFT-MS with a high-volume sampler could also be effective for standoff vapor detection of drugs and additional chemical threats and could be useful for security screening applications such as at mail facilities, border crossings, and security checkpoints.

Keywords: Atmospheric flow tube-mass spectrometry; Explosives; Noncontact sampling; RDX; Standoff detection; Vapor detection.