Demonstration of a Continuous, Real-Time PM2.5 Chemical Speciation Monitor Based on an Aerosol Mass SpectrometerEPA Contract Number: EPD05057
Title: Demonstration of a Continuous, Real-Time PM2.5 Chemical Speciation Monitor Based on an Aerosol Mass Spectrometer
Investigators: Worsnop, Douglas R.
Small Business: Aerodyne Research Inc.
EPA Contact: Manager, SBIR Program
Project Period: April 1, 2005 through June 30, 2006
Project Amount: $225,000
RFA: Small Business Innovation Research (SBIR) - Phase II (2005) Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , SBIR - Air Pollution , Small Business Innovation Research (SBIR)
This Phase II research project addresses the need for improved monitoring technologies for continuous particulate mass and chemical speciation of ambient aerosols. Aerodyne Research, Inc., will develop a prototype Aerosol Chemical Speciation Monitor (ACSM) that measures ambient aerosol mass and chemical composition of nonrefractory submicron aerosol particles in real time, which will provide quantitative measurements of particulate ammonium, nitrate, sulfate, chloride, and organics. The ACSM will be designed to run autonomously for extended periods of time and will need no expensive post-processing analysis.
The ACSM will be based on technology developed for Aerodyne Research, Inc.’s Aerosol Mass Spectrometer (AMS) instrument, including the inlet for efficient particle sampling and the mass spectrometric detection for quantitative mass measurements. The AMS has been deployed successfully in more than 20 national and international field campaigns and has participated in several intercomparisons with a variety of independent instruments, which highlight the capability of the AMS to measure quantitatively and classify particulate inorganics (i.e., ammonium, nitrate, sulfate, and chloride) and organics (i.e., primary combustion and oxidized secondary compounds) in real-time. The value of the AMS as a state-of-the-art aerosol research tool is underscored by its commercial success (34 have been delivered to date).
In Phase I, Aerodyne: (1) tested a proof-of-concept ACSM by intercomparing with the AMS and with filter-based measurements of aerosol composition; (2) evaluated a prototype design for a smaller, lighter weight vacuum chamber; and (3) quantified collection efficiencies for various particle types and sizes. Successful completion of the Phase I tasks showed that the proposed ACSM will have the sensitivity and time response to be of value to the aerosol-monitoring community.
In Phase II, Aerodyne will construct a prototype ACSM and evaluate its performance for continuous monitoring applications. Specific tasks include: (1) further improvement to particle collection efficiency; (2) laboratory evaluation of the prototype ACSM; (3) development of data acquisition software; and (4) intercomparison of the ACSM with the AMS and with filter-based PM2.5 particulate mass and chemical speciation methods. A Phase II option will develop a dual chopper scheme for measuring particle size distributions.
The ACSM will be a simple, robust, modestly priced aerosol chemical speciation instrument ideal for routine monitoring of local and regional air quality; for continuous emissions monitoring at hazardous waste incinerators, power plants, and manufacturing facilities; and for process control monitoring. In addition, the ACSM will find applications in research studies of air pollution, health effects of particulate matter, engine design, and other research areas requiring aerosol measurements.