Research Projects

NIR-LDI-AMS Ion Source  Soft Ionization Aerosol Mass Spectrometry:  Near InfraRed Laser Desorption/Ionization (NIR-LDI) and Photoelectron Resonance Capture Ionization (PERCI) are being developed for the analysis of atmospheric organic particles. These soft ionization sources, in conjunction with aerosol mass spectrometry, give us unprecedented clarity into the composition of these chemically complex particles. The high sensitivity of the two permit us to make measurements at atmospherically relevant aerosol mass loadings.
  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. Meas. Tech. Discuss., 2010, 3, 2013-2033.

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., 2006, 258, 120-133. 
  Secondary Organic Aerosol: Organic particulate in the atmosphere has numerous sources. We are especially interested in the conversion of volatile organic compounds (VOCs) to particulate by reaction with atmospheric gases. So-called secondary organic aerosol (SOA) can make up to 80% of the particulate mass for submicron particles. As such, its formation and chemical aging is important to atmospheric processes, such as cloud formation, thereby impacting global change.
  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 promary and secondary organic aerosols under low loading conditions," Anal. Chem., 2010,submitted.

Zahardis, J.; Geddes, S.; Petrucci, G. "The ozonolysis of primary aliphatic amines in fine particles" Atmos. Chem. Phys. 2008, 8, (5), 1181-1194. 
Lungs  In vitro particle toxicology: Respirable fine particles can be detrimental to human health. Their cytotoxicity is often estimated by in vitro exposures; however, current exposure methodologies do not adequately represent real-world exposures. We are using a novel electrostatic dosing system to expose aerosol particles directly to lung cells grown at the air liquid interface, permitting more accurate assesment or respirable particulate.
  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, 2008, 22, 1768-1774.