Source Characterization of Airborne Particles on a Single-Particle BasisEPA Grant Number: U915354
Title: Source Characterization of Airborne Particles on a Single-Particle Basis
Investigators: Silva, Philip J.
Institution: University of California - Riverside
EPA Project Officer: Boddie, Georgette
Project Period: January 1, 1998 through January 1, 2000
Project Amount: $53,624
RFA: STAR Graduate Fellowships (1998) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Chemistry and Materials Science
The objective of this research project is to perform chemical analysis of particulate emissions from several primary sources of particulate pollution on a single-particle basis. The results will be used to perform the first source apportionment of airborne particles using a real-time, single-particle technique.
Aerosol time-of-flight mass spectrometry (ATOFMS) is a single-particle analysis technique with real-time capabilities. ATOFMS yields data on both the chemical composition and the aerodynamic size of individual particles. By obtaining a size and chemical composition for each individual particle, it is possible to obtain a unique “fingerprint” for different types of particles. These fingerprints can be obtained for various particle sources during emissions tests. Once obtained, the particle fingerprint can be used to identify particles based on their source in ambient samples. Using these fingerprints, ambient data can be used to assess the relative contribution of each source to ambient particulate pollution and track the diurnal variation of each source contribution in the atmosphere.
This study will be the first attempt to use a single-particle mass spectrometry technique for source apportionment. Therefore, emphasis will be placed on the method to convert single-particle data into valid source contributions. This research project will show the potential for using single-particle data for source apportionment and also discuss the difficulties involved. It is expected that source apportionment can be accomplished with more precision using ATOFMS than using a conventional mass balance of bulk chemical data, because particle types can be counted rather than having to deconvolute source profiles of numerous different particle types.