Radney, James G. Zangmeister, Christopher D. Measurement of Gas and Aerosol Phase Absorption Spectra across the Visible and Near-IR Using Supercontinuum Photoacoustic Spectroscopy We demonstrate a method to measure the absorption spectra of gas and aerosol species across the visible and near-IR (500 to 840 nm) using a photoacoustic (PA) spectrometer and a pulsed supercontinuum laser source. Measurements of gas phase absorption spectra were demonstrated using H<sub>2</sub>O<sub>(g)</sub> as a function of relative humidity (RH). The measured absorption intensities and peak shapes were able to be quantified and compared to spectra calculated using the 2012 High Resolution Transmission (HITRAN2012) database. Size and mass selected nigrosin aerosol was used to measure absorption spectra across the visible and near-IR. Spectra were measured as a function of aerosol size/mass and show good agreement to Mie theory calculations. Lastly, we measured the broadband absorption spectrum of flame generated soot aerosol at 5% and 70% RH. For the high RH case, we are able to quantifiably separate the soot and water absorption contributions. For soot, we observe an enhancement in the mass specific absorption cross section ranging from 1.5 at 500 nm (<i>p</i> < 0.01) to 1.2 at 840 nm (<i>p</i> < 0.2) and a concomitant increase in the absorption Ångström exponent from 1.2 ± 0.4 (5% RH) to 1.6 ± 0.3 (70% RH). soot;measure absorption spectra;RH;2O;supercontinuum laser source;Aerosol Phase Absorption Spectra;PA;2012 High Resolution Transmission;water absorption contributions;broadband absorption spectrum;Mie theory calculations;gas phase absorption spectra;Supercontinuum Photoacoustic SpectroscopyWe;840 nm;aerosol;HITRAN 2015-07-21
    https://acs.figshare.com/articles/journal_contribution/Measurement_of_Gas_and_Aerosol_Phase_Absorption_Spectra_across_the_Visible_and_Near_IR_Using_Supercontinuum_Photoacoustic_Spectroscopy/2147827
10.1021/acs.analchem.5b01541.s001