On-Line Organic Aerosol Analysis by Advanced Chemical Ionization Mass Spectrometry

78357 Better measurement technologies for rapid, in situ analysis of carbonaceous aerosols is a critical need for DOE research programs in climate change and clean vehicle technology. The identification and quantification of both the vapor and particulate phases of these compounds, as well as the determination of their natural abundance under typical atmospheric conditions, has not been established and will not be known until better measurement capabilities are available to the scientific community. Recognizing the need to better characterize and quantify the organic aerosol as a dynamic system of vapor and condensed phase species, this project will develop a true aerosol mass spectrometer for on-line analysis of both gas phase and particulate phase organics. Phase I will extend the capability of chemical ionization mass spectrometry to organic aerosol analysis by developing and incorporating a high flow particle sampler into the ionization chamber of the Proton Transfer Reaction Mass Spectrometer (PTR-MS). A semi-continuous approach will be used that allows the PTR-MS to measure organic vapor constituents during the particle collection period (seconds to minutes) followed by a ¿bulk¿ analysis of the collected particles. This multi-phase measurement approach will thus allow a more fundamental understanding of the organic aerosol as a dynamic mixture of vapor and condensed products. Commercial Applications and Other Benefits as described by the awardee: The aerosol mass spectrometer instrumentation can meet important needs in the academic research community, state and federal air monitoring programs, industrial monitoring, and the military and civilian defense market. The sources and composition of carbonaceous particles ultimately could have an impact on public policy decisions regarding regional air quality and global climate change.