Analysis of the volatile chemical markers of explosives using novel solid phase microextraction coupled to ion mobility spectrometry

Abstract

Ion mobility spectrometry (IMS) is routinely used in screening checkpoints for the detection of explosives and illicit drugs but it mainly relies on the capture of particles on a swab surface for the detection. Solid phase microextraction (SPME) has been coupled to IMS for the preconcentration of explosives and their volatile chemical markers and, although it has improved the LODs over a standalone IMS, it is limited to sampling in small vessels by the fiber geometry. Novel planar geometry SPME devices coated with PDMS and sol-gel PDMS that do not require an additional interface to IMS are now reported for the first time. The explosive, 2,4,6-trinitrotoluene (TNT), is sampled with the planar SPME reaching extraction equilibrium faster than with fiber SPME, concentrating detectable levels of TNT in a matter of minutes. The surface area, capacity, extraction efficiency, and LODs are also improved over fiber SPME allowing for sampling in larger volumes. The volatile chemical markers, 2,4-dinitrotoluene, cyclohexanone, and the taggant 4-nitrotoluene have also been successfully extracted by planar SPME and detected by IMS at mass loadings below 1 ng of extracted analyte on the planar device for TNT, for example.

The Development of an Optimized System of Narcotic and Explosive Contraband Mimics for Calibration and Training of Biological Detectors

“…the interface is not considered robust). Further experimentation has been performed by Guerra et al using a novel planar SPME device which negates the need for varying fiber interfaces [98]. This geometry (~ 65-70µm thick) increases the surface area and volume which enhances analyte recovery.…”

Headspace Analysis of Smokeless Powders: Development of Mass Calibration Methods using Microdrop Printing for Chromatographic and Ion Mobility Spectrometric Detection

“…5. PDMS coated glass slides: The polydimethylsiloxane (PDMS) coated glass slides were developed by Guerra et al, at FIU as an alternate SPME geometry 25 . They have been shown to have effective extractions of organic volatiles from the headspace of target matrices.…”

Fast Detection and Chemical Characterization of Gunshot Residues by CMV-GC-MS and LIBS

“…In a similar study, SPME extraction capability was compared to planar solid phase microextraction for the analysis of explosives in IMS. The results yield greater amount of TNT being extracted by PSPME [Guerra et al, 2008].…”

“…Portable instruments and tools have been developed with several applications in illicit drugs and explosives detection, environmental monitoring, and food authentication [Perr et al, 2005;Guerra et al, 2008;Wong et al, 2013;Huang et al, 2015;Soria et al, 2015]. Some of the instruments that have been adapted for field analysis include: Gas chromatography mass spectrometry (GC-MS), ion mobility spectrometry (IMS), x-ray fluorescence spectroscopy (XRF), and laser induced breakdown spectroscopy (LIBS) [Fortes et al, 2010].…”