Ion Mobility Spectrometry - High Resolution LTQ-Orbitrap Mass Spectrometry for Analysis of Homemade Explosives
Nathan Hagan1, Ilana Goldberg2, Adam Graichen3
1Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD, 20723, USA. nathan.hagan@jhuapl.edu.
Journal of the American Society for Mass Spectrometry
|April 15, 2017
Summary
Coupling ion mobility spectrometry (IMS) with tandem mass spectrometry (MS) enables detailed chemical characterization of homemade explosives (HMEs). This advanced analytical technique improves explosive trace detector (ETD) performance by identifying threat compounds and interfering substances.
Area of Science:
- Analytical Chemistry
- Forensic Science
- Spectrometry
Background:
- Accurate chemical characterization of homemade explosives (HMEs) is crucial for enhancing explosive detection instrumentation.
- Commercial explosive trace detectors (ETDs) can be challenged by complex chemical backgrounds that mimic or mask explosives.
Purpose of the Study:
- To couple atmospheric-pressure drift tube ion mobility spectrometry (IMS) with a commercial tandem mass spectrometry (MS) system for comprehensive chemical analysis.
- To elucidate the composition of ion species from erythritol tetranitrate (ETN), a specific HME, including minor impurities.
- To compare IMS-MS data with stand-alone IMS instruments to improve explosive detection algorithms and performance.
Main Methods:
- Coupling of an atmospheric-pressure drift tube ion mobility spectrometry (IMS) instrument with a commercial tandem mass spectrometry (MS) system (linear ion trap and high-resolution Orbitrap analyzer).
- Utilized accurate mass measurements, isotopic ratios, and tandem MS for detailed characterization of erythritol tetranitrate (ETN).
- Employed gated IMS-MS and high-resolution MS to identify minor impurities indicative of HME source or synthesis route.
Main Results:
- Successfully elucidated the ion species composition of erythritol tetranitrate (ETN) using the coupled IMS-MS system.
- Identified minor impurities in ETN, providing potential indicators of its origin and synthesis.
- Demonstrated improved signature assignments for threat compounds and potential for algorithm modification through comparative analysis with commercial ETDs.
Conclusions:
- The coupled IMS-MS system provides extensive characterization capabilities for threat compounds and interfering background chemicals.
- This analytical approach enhances the understanding of HMEs and aids in optimizing the performance of commercial explosive trace detectors (ETDs).
- Detailed chemical insights gained can lead to modified detection algorithms and improved overall ETD reliability and effectiveness.
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