Laser Power Dependence of Mass Spectral Signatures from Individual Bacterial Spores in Bioaerosol Mass Spectrometry

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• 作者：Paul T. Steele ; Herbert J. Tobias ; David P. Fergenson ; Maurice E. Pitesky ; Joanne M. Horn ; Gregg A. Czerwieniec ; Scott C. Russell ; Carlito B. Lebrilla ; Eric E. Gard ; and Matthias Frank
• 刊名：Analytical Chemistry
• 出版年：2003
• 出版时间：October 15, 2003
• 年：2003
• 卷：75
• 期：20
• 页码：5480 - 5487
• 全文大小：198K
• 年卷期：v.75,no.20(October 15, 2003)
• ISSN：1520-6882

文摘

Bioaerosol mass spectrometry is being developed toanalyze and identify biological aerosols in real time.Characteristic mass spectra from individual bacterialendospores of Bacillus subtilis var. niger were obtainedin a bipolar aerosol time-of-flight mass spectrometer usinga pulsed 266-nm laser for molecular desorption andionization. Spectra from single spores collected at anaverage fluence of ~0.1 J/cm² frequently contain prominent peaks attributed to arginine, dipicolinic acid, andglutamic acid, but the shot-to-shot (spore-to-spore) variability in the data may make it difficult to consistentlydistinguish closely related Bacillus species with anautomated routine. Fortunately, a study of the laser powerdependence of the mass spectra reveals clear trends anda finite number of "spectral types" that span most of thevariability. This, we will show, indicates that a significantfraction of the variability must be attributed to fluencevariations in the profile of the laser beam.