Detection of gram-negative Erwinia herbicola outdoor aerosols with pyrolysis–gas chromatography/ion-mobility spectrometry

✍ Scribed by A. Peter Snyder; Waleed M. Maswadeh; Ashish Tripathi; Jacek P. Dworzanski

• Publisher: John Wiley and Sons
• Year: 2000
• Weight: 842 KB
• Volume: 4
• Category: Article
• ISSN: 1086-900X
• DOI: 10.1002/1520-6521(2000)4:2/3<111::aid-fact5>3.0.co;2-a

✦ Synopsis

Aerosol particulate species of the gram-negative bacterium Erwinia herbicola (EH) were detected by stand-alone, analytical instrumentation in an outdoor western United States desert test site. The device consisted of an aerosol collector interfaced to a quartz-tube pyrolysis-gas chromatography/ion-mobility spectrometer (Py-GC/IMS). The detector is about the size of a shoebox, that is, 12 ؋ 9 ؋ 6 in. Bacterial aerosols and background particulates in the 2 to 10 m-diameter range were collected by a 1000-l/min aerosol concentrator and deposited onto a filter in a quartz tube. Rapid heating to 350 ؇C in 5 s effected vaporization, and a portion of the pyrolyzate was directed into a GC column. The eluate was detected by the atmospheric-pressure-based IMS. A distinct peak in the GC/IMS data window was used to signal the presence of the EH bacterial aerosol. The sensitivity of this method was relatively good in that values down to five EH-containing aerosol particles per liter of air could be detected in approximately 2.5 min.