|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.
|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.