Aerosol Mass Spectrometry via Laser-Induced Incandescence Particle Vaporization

Aerosol particles have important impacts on visibility, acid deposition, climate, and human health. A large fraction of the anthropogenic aerosol is generated from energy-related activities, and carbonaceous species are known to constitute a significant fraction of ambient aerosol mass in many locations. In particular, black carbon (BC), formed in combustion processes, is believed to have a strong influence on the earth¿s climate, due to its strong light-absorbing character. Hence, there is a need for quantitative measurements of the chemical composition, mixing state, and atmospheric transformations of BC-containing aerosols; however, such measurements are largely lacking at present. An innovative thermal desorption, time-of-flight aerosol mass spectrometer has been developed to fill a critical need for size-resolved, quantitative chemical composition data on aerosol particles. This project will develop and implement a new laser-based vaporization technique for this instrument, which will enable full characterization of black carbon components, including their state of internal and external mixing. This laser vaporization module will provide a critical addition to the aerosol mass spectrometer, which at present does not directly measure refractory components such as soot and dust. Commercial Applications and other Benefits as described by the awardee: Beyond atmospheric research, the combined aerosol mass spectrometer and laser vaporization module would have the potential to provide an aerosol measurement capability for a variety of monitoring applications. The instrument is ideally suited for the characterization and control of aerosol emissions from a number of industrial and energy production processes (including semiconductor manufacturing, gas turbines, fluidized bed combustors, diesel combustors, and conventional furnaces) that produce aerosol-laden exhaust.