Accessing the Low-polar Molecular Composition of Boreal and Arctic Peat Burning Organic Aerosol via Thermal Analysis and Ultrahigh-Resolution Mass Spectrometry: Structural Motifs and Their Formation

• Main Authors: Schneider, Eric, Neumann, Anika, Chacón-Patiño, Martha, Somero, Markus, Ruppel, Meri, Ihalainen, Mika, Köster, Kajar, Sippula, Olli, Czech, Hendryk, Rüger, Christopher Paul, Zimmermann, Ralf
• Other Authors: Deutsche Forschungsgemeinschaft, Research Council of Finland
• Format: Other/Unknown Material
• Language: unknown
• Published: American Chemical Society (ACS) 2024
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.26434/chemrxiv-2024-k8ld5; https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/666de2a0c9c6a5c07a8e5f18/original/accessing-the-low-polar-molecular-composition-of-boreal-and-arctic-peat-burning-organic-aerosol-via-thermal-analysis-and-ultrahigh-resolution-mass-spectrometry-structural-motifs-and-their-formation.pdf

Peatland fires emit organic carbon rich particulate matter into the atmosphere. Boreal and Arctic peatlands are becoming more vulnerable to wildfires, resulting in a need for better understanding of the emissions of these special fires. Extractable, non-, and low-polar organic aerosol species emitted from laboratory-based boreal and Arctic peat burning experiments are analyzed by direct-infusion atmospheric pressure photoionization (APPI) ultrahigh-resolution mass spectrometry (UHRMS) and compared to time-resolved APPI UHRMS evolved gas analysis from the thermal analysis of peat under inert nitrogen (pyrolysis) and oxidative atmosphere. The chemical composition is characterized on a molecular level, revealing abundant aromatic compounds that partially contain oxygen, nitrogen or sulfur and are formed at characteristic temperatures. Two main structural motifs are identified: single-core and multicore, and their temperature dependent formation is assigned to the thermal degradation of the lignocellulose building blocks and other parts of peat.