Field Detection and Identification of a Bioaerosol Suite by Pyrolysis-gas Chromatography-ion Mobility Spectrometry

Improvements were made to a pyrolysis-gas chromatography-ion mobility spectrometry (Py-GC-IMS) stand-alone biodetector to provide more pyrolyzate compound information to the IMS detector module. Biological aerosols were disseminated at DRES, Alberta, Canada and the Py-GC-IMS was tested for its ability to detect the biological aerosols. Forty-two trials were conducted and a simple area calculation of the GC-IMS data domain biomarker peaks correlated with the correct bioaerosol challenge in 30 trials (71%). In another 7 trials, the status of an aerosol was determined to be biological in origin. Two additional trials had no discernible, unambiguous GC-IMS biological response, because they were blank water sprays. Reproducible limits of detection were at a concentration of less than 0.5 bacterial analyte-containing particles per liter of air (ACPLA). In order to realize this low concentration, an aerosol concentrator was used to concentrate 2000 liters of air in 2.2 minutes. The current series of outdoor trials has provided a platform to show that the Py-GC-IMS can provide information more specific than a biological or nonbiological analysis to an aerosol when the time of dissemination is unknown to the operator. The Py-GCIMS is shown to be able to discriminate between aerosols of a Gram-positive spore (BG), a Gram-negative bacterium (EH) and a protein (ovalbumin). INTRODUCTION Interest continues in the quest for a device that can detect the presence of biological material in a solid, liquid or aerosol sample. Among the interests of the military with respect to biological detection capabilities, operation scenarios require a need to address early warning of a foreign biological presence at perimeters of military posts, stations, airfields and battlefields. There is also a need to have biological detectors resident on military vehicles including tanks, soldier transport carriers, HUMVEEs, ships and aircraft. Pyrolysis-gas chromatography-ion mobility spectrometry (Py-GC-IMS) has been shown to be a