title: Measured infrared optical cross sections for a variety of chemical and biological aerosol simulants.
abstract: We conducted a series of spectral extinction measurements on a variety of aerosolized chemical and biological simulants over the spectral range 3-13 microm using conventional Fourier-transform IR (FTIR) aerosol spectroscopy. Samples consist of both aerosolized particulates and atomized liquids. Materials considered include Bacillus subtilis endospores, lyophilized ovalbumin, polyethylene glycol, dimethicone (SF-96), and three common background materials: kaolin clay (hydrated aluminum silicate), Arizona road dust (primarily SiO2), and diesel soot. Aerosol size distributions and mass density were measured simultaneously with the FTIR spectra. As a result, all optical parameters presented here are mass normalized, i.e., in square meters per gram. In an effort to establish the utility of using Mie theory to predict such parameters, we conducted a series of calculations. For materials in which the complex indices of refraction are known, e.g., silicone oil (SF-96) and kaolin, measured size distributions were convolved with Mie theory and the resultant spectral extinction calculated. Where there was good agreement between measured and calculated extinction spectra, absorption, total scattering, and backscatter were also calculated.
authors.affiliation: US Army Research Laboratory, Adelphi, Maryland 20783-1145, USA. kgurton@arl.army.mil
authors.forename: Kristan P
authors.initials: KP
authors.lastname: Gurton
authors.forename: David
authors.initials: D
authors.lastname: Ligon
authors.forename: Rachid
authors.initials: R
authors.lastname: Dahmani
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000393:Air Pollutants / Q000032:analysis*; D001412:Bacillus subtilis / Q000302:isolation & purification*; D023482:Bioterrorism / Q000517:prevention & control; D002619:Chemical Warfare Agents / Q000032:analysis; D004129:Dimethylpolysiloxanes / Q000032:analysis; D004391:Dust / Q000032:analysis; D007616:Kaolin / Q000032:analysis; D010047:Ovalbumin / Q000032:analysis*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012828:Silicones / Q000032:analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D002619:Chemical Warfare Agents; D004129:Dimethylpolysiloxanes; D004391:Dust; D012828:Silicones; D007616:Kaolin; D011092:Polyethylene Glycols; C013830:baysilon; D010047:Ovalbumin