Grantee Research Project Results

2000 Progress Report: Real-Time Monitoring of Individual Atmospheric Aerosol Particles: Establishing Correlations Between Particle Size and Chemical Speciation

EPA Grant Number: R826240
Title: Real-Time Monitoring of Individual Atmospheric Aerosol Particles: Establishing Correlations Between Particle Size and Chemical Speciation
Investigators: Prather, Kimberly A.
Institution: University of California - Riverside
EPA Project Officer: Hahn, Intaek
Project Period: February 1, 1998 through January 31, 2001
Project Period Covered by this Report: February 1, 2000 through January 31, 2001
Project Amount: $547,000
RFA: Ambient Air Quality (1997) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air

Objective:

The objectives of this research project involve using a newly developed aerosol analysis technique developed in our laboratory, aerosol time-of-flight mass spectrometry (ATOFMS), for taking real-time measurements of the individual particle size and composition of ambient aerosols in a variety of locations in the United States. ATOFMS couples time-of-flight aerodynamic sizing with laser desorption ionization (LDI) time-of-flight mass spectrometry, simultaneously measuring the size and chemical composition (as anions and cations) of individual aerosol particles in real time. One major objective of this research project involves establishing how particle size and composition vary at different locations. Single-particle signatures will be used to explore particle changes due to aging/chemistry, as well as to obtain information on particle sources in different regions of the United States. These studies will represent the first long-term studies, so efforts will be made to convert the qualitative data into more semiquantitative information on atmospheric particles that can be compared with other gas-phase, particle-phase, and meteorological data to further our understanding of aerosol chemistry on shorter time scales. The original objectives of this research project were modified slightly when the U.S. Environmental Protection Agency (EPA) Particulate Matter (PM) Supersites Program began. Originally, ATOFMS was going to be used for PM sampling primarily in southern California, but when the EPA Supersites Program began, this was viewed as a unique opportunity to perform research on PM in various air masses with unique chemistry across the United States, with the added benefit of having other state-of-the-art PM and gas-phase measurements made simultaneously.

Progress Summary:

During this year of the research project, two papers were submitted on work performed as part of this project, the first providing an overview of the Scripps Institution of Oceanography study, and another one detailing organic amines detected in particles in multiple field studies including Atlanta. In addition, two ATOFMSs were deployed in the Houston, Texas, area as part of the TexAQS 2000 Supersite Program. One ATOFMS was set up in Aldine, which is located in the northern part of Houston. The second ATOFMS was located in the eastern part of the Houston area in La Porte. Both instruments sampled particles continuously from August 20, 2000, to September 19, 2000, a total of 32 days, collecting the size and chemical composition of approximately 1.2 million particles; roughly 21.6 gigabytes of data. Results from the ATOFMS located at both sampling sites indicate that there were distinct size and chemical composition differences. Contributions were observed from local factories and refineries, particularly during the evening hours. In addition, a biomass fire in Louisiana made detectable contributions to PM2.5 mass concentrations during the study. In addition, during this year of the contract, further analysis was performed on the Atlanta dataset acquired in 1999. A chemical bias is apparent in the data and procedures are being developed in an attempt to compensate for this bias in scaled ATOFMS concentrations. The ATOFMS data are being compared with other semicontinuous aerosol composition measurements.

Future Activities:

The TexAQS 2000 data are being imported into a database, and Quality Assurance procedures are being performed on the datasets acquired in Aldine and LaPorte. Comparisons of the scaled data will be made with other semicontinuous measurements taken during the study.

Journal Articles:

No journal articles submitted with this report: View all 23 publications for this project

Supplemental Keywords:

air, aerosol, particulate matter, PM, measurement methods, Southeast, sulfates, organics, mobile sources, tropospheric, marine, chemical transport, visibility, ambient air, atmosphere, environmental chemistry, analytical, pollution, source allocation, real time, chemical analysis., RFA, Scientific Discipline, Air, particulate matter, Environmental Chemistry, tropospheric ozone, Ecology and Ecosystems, Environmental Monitoring, air sampling, ambient aerosol, chemical characteristics, particle size, aerosol time-of-flight mass spectrometry (ATOFMS), real time monitoring, atmospheric transport, chemical composition, chemical speciation sampling, particle transport, air pollution, ambient pollution control, fine particle formation, ambient measurement methods, aerosol sampling

Relevant Websites:

http://atofms.ucsd.edu Exit
http://www.yaada.org Exit

Progress and Final Reports:

Original Abstract

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.