AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Raman Spectra of Individual Particles for Characterization of Atmospheric Aerosol
STEVEN HILL, David Doughty, Alan Wetmore, US Army Research Lab
Abstract Number: 501 Working Group: Bioaerosols
Abstract There is a need for improved instruments which can help characterize individual atmospheric particles without requiring reagents. Intrinsic-fluorescence-based instruments are being used for such characterization. Raman spectra of particles can be far more informative than fluorescence about the chemical composition of individual particles. Although single-particle Raman measurements of atmospheric aerosol have been reported by various researchers, single-particle Raman measurements are not routinely used in atmospheric research.
An instrument which collects particles from air onto a tape, and then measures individual-particle Raman spectra of the collected particles has been developed by Battelle. This instrument is termed the REBS (Resource Effective Bioidentification System). Because the Raman spectra are offset spatially using an image-preserving spectrograph, spectra of several particles can often be recorded simultaneously. Typical measurement times required to measure adequate spectra are within the range of 1 to 60 seconds, depending upon particle size and composition. The REBS can run for up to one month unattended, collecting particles and measuring their spectra. We are exploring the use of this instrument for characterizing harmful aerosols such as infectious particles, allergenic particles such as pollens, fungal spores, and cat allergens, and combustion aerosols generated by burn pits, biomass burning, etc., as well as potentially harmful inorganic particles. Here we illustrate the spectra obtained with laboratory-generated particles and indoor and outdoor combustion generated particles.