AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Ageing at the Molecular Level of the Chemical Fingerprint of Emissions Generated by Wood Burning: A TAG –AMS Smog Chamber Study
AMELIE BERTRAND, Giulia Stefenelli, Emily Bruns, Coty Jen, Simone Pieber, Brice Temime-Roussel, Jay Slowik, Andre Prévôt, Allen H. Goldstein, Imad El Haddad, Henri Wortham, Nicolas Marchand, Aix-Marseille Université, CNRS, LCE FRE 3416
Abstract Number: 494 Working Group: Aerosol Chemistry
Abstract Biomass burning is a predominant source of organic aerosol (OA) during winter months and could potentially be largely underestimated because the secondary fraction of OA generated by these types of emissions is often overlooked. This underestimation is partly due to the large gap that remains in our comprehension of the chemical transformation of primary emissions in the atmosphere. It is only recently that instruments capable of analyzing such complex transformation occurring at its most resoluted level: the molecular level and within a relatively short time frame were developed. The TAG (Thermal Desorption Aerosol Gas Chromatograph) coupled with an HR-ToF-AMS is an online chromatographic system which permits the collection and analysis of the aerosol at the molecular level, with a time resolution of less than an hour. Thus, the TAG-AMS can be deployed on smog chamber studies to offer detailed chemical speciation of the aerosol. Such experiments were carried out in the PSI (Paul Scherrer Institute, Villigen, Switzerland) smog chamber. The goal was to characterize primary and secondary emissions from wood burning. Emissions were generated by a variety of stoves (two traditional logwood stoves and one pellet stove). Primary emissions were then injected into the chamber and photo-oxydized for 4 hours during which 5-7 samples were collected and analyzed by the TAG-AMS. A set of online instrumentations such as PTR-ToF-MS, HR-ToF-AMS, Aethalometer AE33, and SMPS provided auxiliary measurements Molecular identification was further investigated through GCxGC EI-HR ToF MS analysis performed on filter samples. This allows us to look at the evolution of a hundred of fine particulate organic compounds, including but not limited to, levoglucosan and its isomers mannosan and galactosan, and to evaluate the degradation that may occur as well as the implication of such results for marker based source apportionment studies.