Research Projects

  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. Jain, J. Zahardis and G.A. Petrucci, "Soft Ionization Chemical Analysis of Secondary Organic Aerosol from Green Leaf Volatiles Emitted by Turf Grass," Environ. Sci. Technol., 2014, 48, (9), 4835-4843.

R. M. Harvey, J. Zahardis and G.A. Petrucci, "Establishing the Contribution of Lawn Mowing to Atmospheric Aerosol Leverls in American Suburbs," Atmos. Chem. Phys., 2014, 14, 797-812.

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. 
  SOA Phase and Optical Properties:  A method of using an electrostatic low pressure impactor has been developed for measurement of particle bounce (a surrogate for particle phase). In combination with aerosol absorbance (using an integrating sphere) and scatter (using a 3-wavelength nephelometer), we are studying relationships between molecular composition and phase of biogenic secondary organic aerosol (BSOA) and subsequent impact on BSOA optical properties.
  S. Jain, J. Zahardis and G.A. Petrucci, "A new method to measure aerosol particle bounce using a cascade electrostatic low pressure impactor," in preparation for submission to Aerosol Sci. Technol. (2014) 
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.