Chemical discrimination of the particulate and gas phases of miniCAST exhausts using a two-filter collection method

Linh Dan Ngo (1, 2) , Dumitru Duca (1, 3) , Yvain Carpentier (1, 3) , Jennifer A. Noble (1) , Raouf Ikhenazene (1) , Marin Vojkovic (1) , Cornelia Irimiea (4) , Ismael Ortega (4) , Guillaume Lefèvre (5) , Jérome Yon (5) , Alessandro Faccinetto (2) , Eric Therssen (2) , Michael Ziskind (1, 3) , Bertrand Chazallon (1, 3) , Claire Pirim (1, 3) , Cristian Focsa (1, 3)

1 PhLAM - Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523
2 PC2A - Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522
3 PMI - Physique Moléculaire aux Interfaces
4 DMPE, ONERA, Université Paris Saclay [Palaiseau]
5 CORIA - Complexe de recherche interprofessionnel en aérothermochimie

Combustion of hydrocarbons produces both particulate-and gas-phase emissions responsible for major impacts on atmospheric chemistry and human health. Ascertaining the impact of these emissions, especially on human health, is not straightforward because of our relatively poor knowledge of how chemical compounds are partitioned between the particle and gas phases. Accordingly, we propose coupling a two-filter sampling method with a multi-technique analytical approach to fully characterize the particulate-and gas-phase compositions of combustion by-products. The two-filter sampling method is designed to retain particulate matter (elemental carbon possibly covered in a surface layer of adsorbed molecules) on a first quartz fiber filter while letting the gas phase pass through and then trap the most volatile components on a second black-carbon-covered filter. All samples thus collected are subsequently subjected to a multi-technique analytical protocol involving two-step laser mass spectrometry (L2MS), secondary ion mass spectrometry (SIMS), and micro-Raman spectroscopy. Using the combination of this two-filter sampling-multi-technique approach in conjunction with advanced statistical methods, we are able to unravel distinct surface chemical compositions of aerosols generated with different set points of a miniCAST burner. Specifically, we successfully discriminate samples by their volatile, semi-volatile, and non-volatile polycyclic aromatic hydrocarbon (PAH) contents and reveal how subtle changes in combustion parameters affect particle surface chemistry.

Domaines: Environnement et Société; Sciences de l'ingénieur [physics]; Milieux fluides et réactifs

Linh Dan Ngo, Dumitru Duca, Yvain Carpentier, Jennifer A. Noble, Raouf Ikhenazene, et al.. Chemical discrimination of the particulate and gas phases of miniCAST exhausts using a two-filter collection method. Atmospheric Measurement Techniques, 2020, 13 (2), pp.951-967. ⟨10.5194/amt-13-951-2020⟩. ⟨hal-02494441⟩