Grantee Research Project Results
2007 Progress Report: Near Real-Time Speciation of Organic Aerosols for Source Apportionment
EPA Grant Number: R832166Title: 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, 2007 through December 31, 2008
Project Amount: $450,000
RFA: Source Apportionment of Particulate Matter (2004) RFA Text | Recipients Lists
Research Category: Particulate Matter , Air Quality and Air Toxics , Air
Objective:
This project includes five specific objectives: 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 non-existent, for example secondary organic aerosols (SOA), 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; concurrent carbonaceous particulate matter measurements will include semi-continuous OC/EC, GC/MS of collected Hi-Vol aerosol samples, OC/EC on Federal Reference Method (FRM) Samplers for PM2.5, and particulate mass. 5) Develop and refine source apportionment models using the organics data.
Progress Summary:
During the third year of this project, Objectives 4 and 5 were addressed. An initial measurement campaign with PIAMS was performed at the State of Delaware Air Quality Monitoring Site in Wilmington, Delaware for a one week period in the second year of the grant (June 2006). In the third year, the data obtained from this study was analyzed and a manuscript describing the results was published. Rapid concentration changes for a variety of organic species were combined with meteorological data to link some species, such as palmitic and oleic acid, to potential sources. Other species, like PAHs, exhibited no significant wind or diurnal dependence. Some organic compound classes, including n-alkanes and n-alkanoic acids, were found to be in abundance during late night/early morning hours, potentially due to the combined effects of temperature inversion, and fresh emissions in a cooler environment. The high-time resolution data from PIAMS shows that rapid concentration changes of a common individual species can be lost with traditional bulk sampling, and a time resolution of 30 minutes is suggested to accurately represent these changes. A second, more extensive measurement campaign was performed at the same location for 16 days in November 2007. As in the previous campaign, PIAMS spectra were acquired every 3.5 minutes; the entire dataset includes 6247 time points. Other time-resolved data collected during the measurement period were OC/EC, SMPS, NOx, SOx, CO, O3 and PM2.5. In addition, bulk particulate samples collected over 12 hour periods were archived for subsequent GC-MS analysis.
Future Activities:
In the coming year, Objective 5 will be addressed. Data from the November 2007 measurement campaign will be analyzed by factor analysis to identify organic aerosol sources. A manuscript on the results will be prepared for publication.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
| Other project views: | All 9 publications | 5 publications in selected types | All 5 journal articles |
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Dreyfus MA, Johnston MV. Rapid sampling of individual organic aerosol species in ambient air with the photoionization aerosol mass spectrometer. Aerosol Science and Technology 2008;42(1):18-27. |
R832166 (2007) R832166 (Final) |
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Heaton KJ, Dreyfus MA, Wang S, Johnston MV. Oligomers in the early stage of biogenic secondary organic aerosol formation and growth. Environmental Science & Technology 2007;41(17):6129-6136. |
R832166 (2007) R832166 (Final) |
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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. |
R832166 (2005) R832166 (2006) R832166 (2007) R832166 (Final) |
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Supplemental Keywords:
Ambient air, particulates, PAH, organics, monitoring, analytical, measurement methods,, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Air, particulate matter, Environmental Chemistry, Monitoring/Modeling, Environmental Engineering, Environmental Monitoring, atmospheric dispersion models, air sampling, chemical characteristics, airborne particulate matter, emissions monitoring, atmospheric chemistry, real-time monitoring, speciation, modeling studies, environmental measurement, particulate matter mass, air quality model, particulate organic carbon, aerosol analyzers, source apportionment, chemical speciation sampling, particle size measurement, air quality models, analytical chemistry, atmospheric measurements, monitoring of organic particulate matterRelevant Websites:
http://www.udel.edu/chem/johnston Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.