Aerosol Reactions and Raman Analysis of Organic and Bioaerosols

University Of Washington, Seattle WA

Investigators

Abstract

Abstract CTS-9982413 E. James Davis, University of Washington It is proposed to extend Professor Davis' ongoing research on micron-sized aerosol measurement by means of Raman derived spectroscopic techniques, supplemented by the electrodynamic trapping in space of the particulates of interest (electrodynamic balance). Three tasks are proposed: 1) The exploration of aerosol sizes in the submicron range (typical of organic and bioaerosol materials); resonant Raman techniques will be emphasized in this part. It is hoped that atmospheric specie will respond to the use of tunable ultra violet sources in the latter technique. 2) The specific problem of ultra violet induced fluorescence as a contaminant of the Raman signals, will be alleviated by substituting a near-infra-red source. A tunable dye laser (700-800nm) will also be tested for it's suitably in getting clear Raman spectra. 3) This technique (electrodynamic balance + Raman) will be applied to investigate the desulfurization process in power plants stack gases. Some of the processes occurring in electrodynamic balance trapping (e.g. charging) stand in the way of the accuracy necessary to measure the kind of submicrometer particles found in the atmosphere. Also, the procedure has been tailored so far to relatively simplified laboratory conditions. It will be further refined to allow for direct "on-line" environment measurements.