title: Fluorescence spectra of atmospheric aerosol particles measured using one or two excitation wavelengths: comparison of classification schemes employing different emission and scattering results.
abstract: An improved Dual-wavelength-excitation Particle Fluorescence Spectrometer (DPFS) has been reported. It measures two fluorescence spectra excited sequentially by lasers at 263 nm and 351 nm, from single atmospheric aerosol particles in the 1-10 mum diameter size range. Here we investigate the different levels of discrimination capability obtained when different numbers of excitation and fluorescence-emission wavelengths are used for analysis. We a) use the DPFS to measure fluorescence spectra of Bacillus subtilis and other aerosol particles, and a 25-hour sample of atmospheric aerosol at an urban site in Maryland, USA; b) analyze the data using six different algorithms that employ different levels of detail of the measured data; and c) show that when more of the data measured by the DPFS is used, the ability to discriminate among particle types is significantly increased.
authors.affiliation: US Army Research Laboratory, Adelphi, MD 20783, USA. yongle.pan@us.army.mil
authors.forename: Yong-Le
authors.initials: YL
authors.lastname: Pan
authors.forename: Steven C
authors.initials: SC
authors.lastname: Hill
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Pinnick
authors.forename: Hermes
authors.initials: H
authors.lastname: Huang
authors.forename: Jerold R
authors.initials: JR
authors.lastname: Bottiger
authors.forename: Richard K
authors.initials: RK
authors.lastname: Chang