2005 Progress Report: Near Real-Time Speciation of Organic Aerosols for Source ApportionmentEPA Grant Number: R832166
Title: Near Real-Time Speciation of Organic Aerosols for Source Apportionment
Investigators: Johnston, Murray V.
Institution: University of Delaware
EPA Project Officer: Chung, Serena
Project Period: January 1, 2005 through December 31, 2007 (Extended to December 31, 2008)
Project Period Covered by this Report: January 1, 2005 through December 31, 2006
Project Amount: $450,000
RFA: Source Apportionment of Particulate Matter (2004) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air
The objectives of this research project are to: (1) develop a photoionization aerosol mass spectrometer (PIAMS) for near real-time measurement of trace organic constituents in fine particles; (2) couple PIAMS with an aerosol concentrator to reduce the sampling time of PIAMS to 2 minutes or less for ambient urban air; (3) acquire improved PIAMS signatures (source profiles) for those sources where elemental data may be ambiguous or nonexistent, for example secondary organic aerosols, highway traffic, and meat cooking operations; (4) use the concentrator and PIAMS to measure trace organic constituents in fine particles in Wilmington, Delaware, at the State of Delaware, Department of Natural Resources and Environmental Control Air Quality Measurement Site, including concurrent carbonaceous particulate matter (PM) measurements such as semicontinuous organic carbon/elemental carbon (OC/EC), gas chromatography/mass spectroscopy of collected Hi-Vol aerosol samples, OC/EC on Federal Reference Method Samplers for PM2.5, and particulate mass; and (5) develop and refine source apportionment models using the organics data.
During Year 1 of this project, Objectives 1-3 were addressed.
Objective 1: PIAMS was reconfigured for field work, including (1) hardware and software development for automated sample collection and data acquisition; (2) an improved collection probe design, which maintained robust alignment with the particle beam and permitted the probe surface to be cooled to inhibit evaporation of semivolatile compounds; and (3) redesign of vacuum components for robust use in the field.
Objective 2: A mini-versatile aerosol concentration system (m-VACES) was obtained from the University of Southern California and connected to the PIAMS for preliminary measurements of ambient aerosol. In this experiment, outside air was drawn into the laboratory through the m-VACES and sampled by PIAMS at roughly 5-minute intervals. The mass spectra showed ion signals consistent with common sources of organic aerosol, demonstrating that the m-VACES-PIAMS approach is capable of highly time-resolved measurements at ambient levels.
Objective 3: In work related to biogenic source signatures, PIAMS was used during Year 1 to characterize products of the reaction of monoterpenes with ozone.
In the coming year, Objectives 1-4 will be addressed. Objective 1 will be completed and Objective 2 will be furthered through the design and construction of a virtual impactor to match more closely the output flow rate of m-VACES with the input flow rate of PIAMS. Objective 4 will begin with a preliminary field measurement of the m-VACES-PIAMS combination at the State of Delaware Air Quality Measurement Site. Based on the results of this preliminary measurement, additional source signatures (Objective 3) will be acquired.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 9 publications||5 publications in selected types||All 5 journal articles|
||Tolocka MP, Heaton KJ, Dreyfus MA, Wang S, Zordan CA, Saul TD, Johnston MV. Chemistry of particle inception and growth during [alpha]-pinene ozonolysis. Environmental Science & Technology 2006;40(6):1843-1848.||