Archive ouverte HAL – Bulk organic aerosol analysis by PTR-MS: an improved methodology for the determination of total organic mass, O:C and H:C ele- mental ratios and the average molecular formula

Joris Leglise 1 Markus Muller 2 Felix Piel 3 Tobias Otto 4 Armin Wisthaler 5, 6

Joris Leglise, Markus Muller, Felix Piel, Tobias Otto, Armin Wisthaler. Bulk organic aerosol analysis by PTR-MS: an improved methodology for the determination of total organic mass, O:C and H:C ele- mental ratios and the average molecular formula. Analytical Chemistry, American Chemical Society, 2019, ⟨10.1021/acs.analchem.9b02949⟩. ⟨hal-02459530⟩

We have recently shown in this journal (Müller et al., Anal. Chem. 2017, 89, 10889-10897) how a proton-transfer-reaction mass spectrometry (PTR-MS) analyzer measured particulate organic matter in urban atmospheres using the "Chemical Analysis of Aerosol Online" (CHARON) inlet. Our initial CHARON studies did not take into account fragmentation of protonated analyte molecules, which introduced a small but significant negative bias in the determination of bulk organic aerosol parameters. Herein, we studied the ionic fragmentation of 26 oxidized organic compounds typically found in atmospheric particles. This allowed us to derive a correction algorithm for the determination of the bulk organic mass concentration, m OA , the bulk-average hydrogen to carbon ratio, (H:C) bulk, the bulk-average oxygen-to-carbon, (O:C) bulk , and the bulk-average molecular formula, MF bulk. The correction algorithm was validated against AMS data using two sets of published data. Finally, we determined MF bulk of particles generated from the reaction of -pinene and ozone and compared and discussed the results in relation to the literature.

  • 1. ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement
  • 2. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
  • 3. IAU - Institute for Atmospheric and Environmental Sciences [Frankfurt/Main]
  • 4. TROPOS - Leibniz Institute for Tropospheric Research
  • 5. Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck]
  • 6. UiO - University of Oslo