Volume 43, Issue 4 (July 1998)
Identification of Tear Gases in Suspect Spray Cans and Cloth Samples by Ion Mobility Spectrometry
A handheld ion mobility spectrometer was used to characterize the vapors produced at 50°C by the active ingredients of 20 μL samples of commercially available CN and CS tear gas sprays. After separation of the active ingredients of the sprays from their carrier gases and solvents, the spectra obtained are indistinguishable from standards, and can be used as vapor phase “fingerprints” to distinguish between these tear gas agents. The evaporative method used to separate the active ingredients from propellants and solvents was simple, but very effective in removing spectral interferences. We suggest that from the perspectives of speed of response, portability, intrinsic low detection limits, and the secondary information available from ion mobility spectra, these studies illustrate the potential of mobility spectrometry to fulfill forensic requirements for a rapid screening method for suspect spray cans and clothing.