Development and Application of a Mass Spectra-Volatility Database of Combustion and Secondary Organic Aerosol Sources for the Aerodyne Aerosol Mass SpectrometerEPA Grant Number: R831080
Title: Development and Application of a Mass Spectra-Volatility Database of Combustion and Secondary Organic Aerosol Sources for the Aerodyne Aerosol Mass Spectrometer
Investigators: Ziemann, Paul J. , Jimenez, Jose-Luis , Worsnop, Douglas R.
Institution: University of California - Riverside , Aerodyne Research Inc. , University of Colorado at Boulder
EPA Project Officer: Chung, Serena
Project Period: October 1, 2003 through August 14, 2006 (Extended to September 30, 2007)
Project Amount: $409,922
RFA: Measurement, Modeling, and Analysis Methods for Airborne Carbonaceous Fine Particulate Matter (PM2.5) (2003) RFA Text | Recipients Lists
Research Category: Air , Air Quality and Air Toxics , Particulate Matter
There is currently a critical need for real-time methods of organic aerosol particle analysis for use in ambient monitoring, source apportionment, and health effects studies. In this research program, we plan to address this need by developing and applying a thermodenuder-Aerodyne Aerosol Mass Spectrometer (TD-AMS) technique for ambient organic fine particle analysis. The objectives of the project are to (1) construct the thermodenuder and optimize the TD-AMS, (2) use the TD-AMS in laboratory studies to develop a mass spectra-volatility database for the major atmospheric combustion and secondary organic aerosol sources, and (3) apply the database to a TD-AMS study of organic aerosol in the Los Angeles Air Basin.
A thermodenuder will be constructed, tested, and coupled to an AMS and then evaluated and optimized using standard particles. The TD-AMS will then be used to develop a database of mass spectra-volatility signatures for interpreting ambient organic aerosol TD-AMS data. TD-AMS measurements will be made on laboratory-generated organic aerosols from the major primary sources (combustion of gasoline, diesel fuel, and wood, and meat cooking) and the major secondary sources (oxidation of aromatics, alkanes and alkenes, and biogenic compounds by OH and NO3 radicals and O3) of fine particle organics. A field study will then be carried out in the Los Angeles Air Basin under conditions when both primary and secondary organic aerosols should be present, and the TD-AMS data analyzed using the new database.
The results of this project will lead to a powerful new technique for the chemical characterization of atmospheric organic PM2.5, which through its application will improve the understanding of organic aerosol formation mechanisms and sources, and add valuable new data for use in source apportionment modeling. Such data can aid in the evaluation of the effects of fine particulate matter on human health and the environment, and can be used to develop more accurate air pollution models. This will allow for more efficient targeting of aerosol sources in pollution control strategies. The TD-AMS technique should see widespread use in the aerosol community since the AMS is currently used by more than 20 research groups for quantitative analysis of size-resolved chemical composition of ambient aerosol particles.