Professor — Analytical Chemistry, Aerosols Analysis, Mass Spectrometry

Research and/or Creative Works

Our research focuses on developing new methods for the physical and chemical analysis of organic aerosols and then applying these methods to questions of relevance to the atmosphere. Our approach is centered on three pillars: (1) identify volatile compound (VOC) emissions from biogenic sources that are precursors to organic aerosols; (2) understand the fundamental chemical mechanisms by which these aerosols are formed and aged in the atmosphere; and, (3) correlate their chemical properties with their phase and optical properties. To this end, we (1) investigate new VOC sources, measuring their VOC emission profiles and evaluating their organic aerosol forming potential; (2) continue to develop novel soft-ionization mass spectrometric methods to facilitate deconvolution of the complex chemical makeup of organic aerosols; and (3) use a novel method developed in our laboratory to measure particle bounce as a surrogate for particle phase. Ultimately, the unique data we acquire serves to improve our understanding of atmospheric organic chemistry and aids in improving the predictive capabilities of atmospheric chemistry models.


J. Zahardis, S. Geddes and G.A. Petrucci, "Improved Understanding of Atmospheric Organic Aerosols via Innovations in Soft Ionization Aerosol Mass Spectrometry", Anal. Chem., 83 (7), 2409-2415 (2011) [Cover Feature Article]

S. Geddes, B. Nichols, S. Flemer Jr., J. Eisenhauer, J. Zahardis and G.A. Petrucci, "Near-Infrared Laser Desorption/Ionization Aerosol Mass Spectrometry for Investigating Primary and Secondary Organic Aerosols under Low Loading Conditions," Anal. Chem., 82(19) 7915-7923 (2010).

S. Geddes, B. Nichols, K. Todd, J. Zahardis and G.A. Petrucci, "Near-infrared laser desorption/ionization aerosol mass spectrometry for measuring organic aerosol at atmospherically relevant aerosol mass loadings", Atmos. Measu. Tech., 3, 1175-1183 (2010).

S. Geddes, J. Zahardis and G.A. Petrucci, "Chemical transformations of peptide containing fine particles: oxidative processing, accretion reactions and implications to the atmospheric fate of cell-derived materials in organic aerosol", J. Atmos. Chem., 63(3), 187-202 (2009).

S. Geddes, J. Zahardis, J. Eisenhauer, and G.A. Petrucci, "Low energy photoelectron capture resonance ionization aerosol mass spectrometry of small peptides with Cysteine residues: Cys-Gly, -Glu-Cys and glutathione" Int. J. Mass Spectrom, 282(1-2), 13-20 (2009).

J.P. Stevens, J. Zahardis, M. MacPherson, B.T. Mossman and G.A. Petrucci, "A new method for quantifiable and controlled dosage of particulate matter for in vitro studies: the electrostatic particulate dosage and exposure system (EPDExS)",Toxicol. In Vitro, 22, 1768-1774 (2008).

K.A. Puzey, P.J. Gardner, V.K. Petrova, C.W. Donnelly and G.A. Petrucci, "Automated species and strain identification of bacteria in complex matrices using FTIR spectroscopy", Proceedings of the SPIE (International Society for Optical Engineering), Chemical, Biological, Radiological, Nuclear, Explosive Sensors IX, 2008

J. Zahardis, S. Geddes and G.A. Petrucci, "The ozonolysis of primary aliphatic amines in single and multicomponent fine particles," Atmos. Chem. Phys., 8, 1181-1194 (2008).

J. Zahardis, S. Geddes and G.A. Petrucci, "Detection of free amino acids in proxies of marine aerosol by photoelectron resonance capture ionization aerosol mass spectrometry", Int. J. Environ. Anal. Chem., 88 (3), 177-184 (2008)

B.J. Holmes and G.A. Petrucci, "Oligomerization of levoglucosan by Fenton chemistry in proxies of biomass burning aerosols", J. Atmos. Chem., 58, 151-166 (2007).

A.L. Hunt, G.A. Petrucci, P.R. Bierman and R.C. Finkel, "Investigation of metal matrix systems for cosmogenic 26Al analysis by accelerator mass spectrometry", Nucl. Instrum. Methods Phys. Res., Sect. B, 260, 633-636 (2007)

J. Zahardis and G.A Petrucci, "The oleic acid-ozone heterogeneous reaction system: products, kinetics, secondary chemistry, and atmospheric implications of a model system - a review", Atmos. Chem. Phys., 7, 1237-1274 (2007).

A.L. Hunt and G.A. Petrucci, "On-line organic aerosol analysis by mass spectrometry", Encyclopedia of Mass Spectrometry, Vol. 6, Elsevier (2006).

A.L. Hunt and G.A. Petrucci, "Photoelectron resonance capture ionization mass spectrometry (PERCI-MS)", Encyclopedia of Mass Spectrometry, Vol. 6, Elsevier (2006).

B.J. Holmes and G.A. Petrucci, "Water-soluble oligomer formation from acid catalyzed reactions of levoglucosan in proxies of atmospheric aqueous aerosols", Environ. Sci. Technol., 40 (11) 4983-4989, (2006).

J. Zahardis, B. W. LaFranchi and G.A. Petrucci, "Photoelectron Resonance Capture Ionization Mass Spectrometry of Fatty Acids in Olive Oil", Eur. J. Lipid Sci. Technol. 108 (11), 925-935,(2006).

B.W. LaFranchi and G.A. Petrucci, "A comprehensive characterization of photoelectron resonance capture ionization aerosol mass spectrometry for the quantitative and qualitative analysis of organic particulate matter," Int. J. Mass Spectrom., 258 (1-3), 120-133, (2006).

J. Zahardis, B.W. Lafranchi and G.A. Petrucci, "The heterogeneous reaction of particle-phase methyl esters and ozone elucidated by photoelectron resonance capture ionization: direct products of ozonolysis and secondary reactions leading to the formation of ketones", Int. J. Mass Spectrom. 253 38-47, (2006).

A.L. Hunt, G.A. Petrucci, P. Biermann and R.G. Finkel, "Metal matrices to optimize ion beam currents for accelerator mass spectrometry", Nucl. Instrum. Methods Phys. Res., Sect. B, 243, 216-222, (2006).

J. Zahardis, B.W. LaFranchi and G.A. Petrucci, "Direct Observation of Polymerization in the Oleic Acid-Ozone Heterogeneous Reaction System by Photoelectron Resonance Capture Ionization Aerosol Mass Spectrometry" Atmos. Environ. 40, 1661-1670, (2006)

Areas of Expertise and/or Research

Analytical chemistry, mass spectrometry, environmental aerosols


  • Ph.D., University of Florida, Gainesville, FL, 1993
  • Postdoctoral Fellowship, European Commission — Joint Research Center, Ispra, Italy 1993–1994


  • (802) 656-0957
Office Location:

Discovery Hall W308