Grantee Research Project Results
Highly Time-Resolved Source Apportionment Techniques for Organic Aerosols Using the Aerodyne Aerosol Mass Spectrometer
EPA Grant Number: R832161Title: Highly Time-Resolved Source Apportionment Techniques for Organic Aerosols Using the Aerodyne Aerosol Mass Spectrometer
Investigators: Jimenez, Jose-Luis , Schauer, James J. , Hannigan, Michael P. , Zhang, Qi
Institution: University of Colorado at Boulder , University of Wisconsin - Madison
EPA Project Officer: Chung, Serena
Project Period: December 1, 2004 through November 30, 2007 (Extended to November 30, 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:
The overall objective of this proposed project is to develop, validate, and apply fine particulate matter (PM) source apportionment techniques for measurements made with the Aerodyne Aerosol Mass Spectrometer (AMS). The AMS is the only current real-time instrument that provides quantitative size-resolved organic aerosol data with a time resolution of a few minutes. AMS organic data have less fragmentation and thus are more specific for source apportionment than data from laser-ablation mass spectrometers. We expect a number of instruments being developed to improve organic detection specificity via chemical ionization and/or photoionization. The proposed efforts will focus on AMS data but will provide the foundation for using other such data for source apportionment.
Approach:
Preliminary results (section E.2.3) indicate that AMS organic aerosol data are sufficiently specific to address the critical need for source apportionment of organic aerosols with very high time resolution. We will investigate various approaches for apportioning AMS organic data, including: (a) custom techniques that take advantage of our understanding of the data; (b) Advanced Data Mining techniques currently being developed by the University of Wisconsin (under NSF funding); and (c) standard multivariate receptor models (e.g., UNMIX and PMF). We will test all models with simulated AMS data with several overlapping sources. We will then apply these methods to the well-characterized AMS datasets from the Pittsburgh, New York City, and Houston EPA Supersites. We will carry out a new field campaign (using three AMSs) with two objectives: (1) compare with the well-established chemical mass balance (CMB) method from collocated organic molecular marker data; and (2) demonstrate the improvements in organic source apportionment from three new techniques designed to improve the sensitivity and selectivity of the AMS for organic aerosols: a time-of-flight mass spectrometer (replacing the quadrupole used in the standard AMS), low temperature vaporization, and thermal denuding.
Expected Results:
The primary result of this project will be to demonstrate and validate source apportionment of organic aerosols with very high time resolution using AMS data. The results of this project can have a rapid and broad impact because the techniques developed here can be used by many researchers around the world, including the more than 25 research groups with an AMS. In addition, these techniques and algorithms will also provide the foundation for source apportionment using data from emerging and future quantitative aerosol mass spectrometers.
Publications and Presentations:
Publications have been submitted on this project: View all 115 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 31 journal articles for this projectSupplemental Keywords:
multivariate methods, single particle mass spectrometry, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Air Quality, Environmental Chemistry, Monitoring/Modeling, Environmental Monitoring, Environmental Engineering, particulate organic carbon, atmospheric dispersion models, atmospheric measurements, model-based analysis, time resolved apportionment, source apportionment, chemical characteristics, emissions monitoring, environmental measurement, airborne particulate matter, air quality models, air quality model, air sampling, speciation, particulate matter mass, analytical chemistry, aerodyne aerosol mass spectrometry, monitoring of organic particulate matter, modeling studies, chemical transport models, real-time monitoring, aerosol analyzers, chemical speciation sampling, particle size measurementProgress and Final Reports:
The 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.