AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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Comparison of Evolving Fluorescence Signatures of Biological Particles Measured with an SPFS, UV APS, and WIBS as a Function of Aging in a Rotating Drum
SEAN KINAHAN, Yong-Le Pan, Don Collins, Matthew Tezak, Keiko Salazar, Mark Coleman, Andres Sanchez, Joshua Santarpia, Sandia National Laboratories
Abstract Number: 633 Working Group: Bioaerosols
Abstract Fluorescence measurement techniques are routinely used for characterizing bioaerosols in the environment and laboratory, both when they are present as isolated populations and as parts of more complex aerosol backgrounds. The light-induced fluorescence (LIF) techniques used here employ 263- or 280-nm light to excite fluorescence from the amino acids tryptophan and tyrosine, and 351-, 355-, or 370-nm light to excite fluorescence from NADH and flavins. As biological aerosols age due to exposure to evolving environmental conditions their fluorescent signatures are altered. We used a Goldberg rotating drum to age biological simulants during a series of experiments designed to assess changes resulting from exposure to varying relative humidity, UV intensity, and concentrations of ozone and other pollutants. Fluorescence signatures were measured using the ARL Single Particle Fluorescence Spectrometer (SPFS), the TSI Inc. Ultraviolet Aerodynamic Particle Sizer, and the DMT Wideband Integrated Bioaerosol Sensor (WIBS-4A). We sought both to study the effects of aging and to compare the response of the three instruments, which employ different LIF excitation sources and sizing mechanisms. The changing strengths and characteristics of the fluorescence signatures of a variety of biological particles, including MS-2 bacteriophage and Bacillus thuringiensis, are presented.