Submitted to: Journal of Separation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2002
Publication Date: 5/1/2003
Citation: Eiceman, G.A., Tarassov, A., Funk, P.A., Hughs, S.E., Nazarov, E.G., Miller, R.A. Discrimination of combustion fuel sources using gas chromatograhphy-planar field asymmetric-waveform ion mobility spectrometry. Journal of Separation Science. 2003. v. 26(6/7). p. 585-593. Interpretive Summary: Cotton gins and warehouses would benefit from fire protection alarms that could distinguish between smoke caused by burning cotton and smoke from other, non-alarm sources (such as fork trucks). The planar field asymmetric-waveform ion mobility spectrometer (PFAIMS) is a low cost analytical device that works in ambient air. It makes a sensitive and selective detector when coupled with a gas chromatograph (GC). The GC separates volatile organic compounds (VOC) found in smoke based on their size. The PFAIMS separates VOC based on ion mobility. Combining the two instruments provides two dimensions of resolution. Even very trace amounts of a substance can be positively identified rapidly and at low cost. This technology begs commercialization.
Technical Abstract: Smoke plumes from cotton, paper, grass and cigarettes and emissions from a gasoline engine were sampled using solid-phase microextraction (SPME) and samples were analyzed for volatile organic compounds(VOC) using gas chromatography-mass spectrometry (GC-MS). Chemical compositions were sufficiently distinct to allow source identification. Unfortunately, advanced smoke detectors based on GC-MS would be too slow and expensive for most applications. Direct sampling of smoke by atmospheric pressure chemical ionization-mass spectrometry produced a complex response, demonstrating that VOC in smoke were suitable for gas phase chemical ionization. The complexity also indicated the necessity of chromatographic prefractionation. Planar Field Asymmetric-waveform Ion Mobility Spectrometry (PFAIMS) as a capillary GC detector generated chemical information orthogonal to GC retention times. The combination of SPME preconcentration and the additional information provided by the PFAIMS detector yielded unique patterns from smoke from each fuel. Reconstruction chromatograms extracted from the PFAIMS scans indicated sufficient resolution of chemical constituents could be completed in less than five minutes with little loss of analytical information. These first measurements suggest that a GC-PFAIMS instrument operating at ambient pressure in air might result in a compact and convenient fuel specific smoke alarm at a reasonable cost.