HR: 14:10h
AN: B53B-03    [Abstracts]
TI: Detection of Biomass in New York City Aerosols: Light Scattering and Optical Fluorescence Techniques
AU: * Niebauer, M
B53B-03 AF: Department of Earth and Atmospheric Sciences City College of New York, 138th & Convent Avenue, New York, NY 10031 United States
AU: Alimova, A
EM: aalimova@sci.ccny.cuny.edu
AF: Department of Physics City College of New York, 138th & Convent, New York, NY 10031 United States
AU: Katz, A
EM: akatz@sci.ccny.cuny.edu
AF: Department of Physics City College of New York, 138th & Convent, New York, NY 10031 United States
AU: Xu, M
EM: minxu@sci.ccny.cuny.edu
AF: Department of Physics City College of New York, 138th & Convent, New York, NY 10031 United States
AU: Rudolph, E
EM: lizrud@sci.ccny.cuny.edu
AF: Department of Earth and Atmospheric Sciences City College of New York, 138th & Convent Avenue, New York, NY 10031 United States
AU: Steiner, J
EM: steiner@sci.ccny.cuny.edu
AF: Department of Earth and Atmospheric Sciences City College of New York, 138th & Convent Avenue, New York, NY 10031 United States
AU: Steiner, J
EM: steiner@sci.ccny.cuny.edu
AF: PhD Program in Earth and Environmental Sciences City University of New York, 365 5th Avenue, New York, NY 10016 United States
AU: Alfano, R R
EM: alfano@sci.ccny.cuny.edu
AF: Department of Physics City College of New York, 138th & Convent, New York, NY 10031 United States
AB: Optical spectroscopy is an ideal method for detecting bacteria and spores in real time. Optical fluorescence spectroscopy examination of New York City aerosols is used to quantify the mass of bacteria spores present in air masses collected at 14 liters/minute onto silica fiber filters, and on silica fiber ribbons using an Environmental Beta Attenuation Monitor manufactured by MetOne Instruments configured for the PM2.5 fraction. Dipicolinic acid (DPA), a molecule found primarily in bacterial spores, is the most characteristic component of spores in trial experiments on over 200 collected aerosol samples. DPA is extracted from the spores using a heat bath and chelated with Terbium. The DPA:Tb is detected by measuring its characteristic fluorescence with emission bands at 490, 545 and 585 nm for 270 nm excitation. Light scattering also measures the size distribution for a number of a variety of bacteria - Bacillus subtilis (rod shaped), Staphylococcus aureus (spherical) and Pseudomonas aeruginosa (short rods) establishing that optical techniques satisfactorily distinguish populations based on their variable morphology. Size and morphology are obtained by applying a variation of the Gaussian Ray Approximation theory of anomalous diffraction theory to an analysis of the transmission spectra in the range of 0.4 to 1.0 microns. In test experiments, the refractive index of the inner spore core of Bacillus subtilis decreases from 1.51 to 1.39 while the spore radius enlarges from 0.38 to 0.6 micrometers. Optical determinations are verified by oil-immersion techniques and by scanning electron microscope measurements. Characterization of spores, germinating spore materials, and bacteria is considered vital to tracing bacteria in the environment, for the development of life-detection systems for planetary exploration, monitoring pathogens in environmental systems, and for the preparation of anti-terrorism strategies.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 4801 Aerosols (0305, 4906)
DE: 4906 Aerosols (0305, 4801)
SC: Biogeosciences [B]
MN: Fall Meeting 2005