10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Aerosol Chemistry Investigations by CHARON-PTR-ToF-MS

MARKUS MUELLER, Joris Leglise, Tobias Otto, Todd Rogers, Armin Wisthaler, IONICON Analytik GmbH., Innsbruck, Austria

     Abstract Number: 90
     Working Group: Aerosol Chemistry

Abstract
Scientific progress in organic aerosol chemistry is still hampered by the lack of analytical methods that comprehensively and quantitatively characterize the organic composition of particulate matter in the atmosphere. Recently, the "Chemical Analysis of Aerosol Online" (CHARON) particle inlet has been introduced, enabling proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) instruments to characterize particulate-bound organics down to pg m-3 levels. Herein, we will demonstrate the potential of the CHARON-PTR-ToF-MS for aerosol chemistry and physics studies. Based on results from experiments on 36 pure compounds we will show how qualitative (elemental composition) and quantitative analyses (mass concentrations) can be corrected for biases caused by analyte ion fragmentation in the PTR-ToF-MS analyzer. We will further show how bulk elemental ratios (O:C, H:C) of urban aerosol and monoterpene-derived SOA compare with parallel TOF-AMS measurements and reported literature values. We will also compare the volatility of monoterpene-derived SOA on a molecular level as directly measured in thermodenuder experiments and predicted from the 2D-volatility basis set using the CHARON-PTR-ToF-MS-derived chemical composition. The implications for the aerosol chemistry of monoterpene-derived SOA will be discussed.

The development of CHARON was funded through the PIMMS ITN, which was supported by the European Commission’s 7th Framework Programme under grant agreement number 287382. J.L. and T.O. received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 690958 (MARSU).