- 1Institute for Atmospheric and Earth System Research (INAR) / Physics, University of Helsinki, Helsinki, Finland
- 2Karsa Ltd, A. I. Virtasen aukio 1, 00560 Helsinki, Finland
- 3Aerosol Physics Laboratory, Tampere University, 33720 Tampere, Finland.
- 4Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland.
Offline filter sampling of aerosols is a cost-effective and easily deployable method for long-term measurements. However, the subsequent analysis can be cumbersome and time-consuming. Measuring fine particulate matter with an aerodynamic diameter of up to 2.5μm (PM2.5) is essential in air pollution studies. To understand the role of organic aerosols (OA) in the atmosphere, particularly regarding climate and health effects, it is crucial to know their molecular composition. Typically, such data is gathered through offline filter sampling and laboratory analysis (Daellenbach et al., 2020; Cai et al., 2023).
Currently, there are many extraction methods for collected PM2.5 filters (see e.g., Roper et al. (2019)). Most of these methods require several stages of preparation before analysis can begin. This often involves cutting smaller pieces from the used filters and then performing steps such as sonication, rinsing, drying, dissolving, and nebulizing before the sample is finally analyzed.
We propose a more streamlined workflow. The entire collected filter is placed in a thermal desorption multi-scheme chemical ionization inlet coupled to an Orbitrap mass spectrometer (TD-MION-Orbitrap, see e.g., Partovi et al. (2023)). The MION allows for fast switching between multiple reagents, and the Orbitrap provides high mass resolution. While previous studies have successfully used TD-CIMS for offline analysis of PM (e.g., Cai et al., 2023), our method offers a user-friendly, preparation-free analysis process.
We hope to get the opportunity to present data from ambient filters collected in Helsinki – in a comparison to existing analysis methods – along with initial results from these early stages of the project.
References
Cai, J. et al. (2023). Characterization of offline analysis of particulate matter with FIGAERO-CIMS. Atmospheric Measurement Techniques, 16(5), 1147-1165.
Daellenbach, K. R. et al. (2020). Sources of particulate-matter air pollution and its oxidative potential in Europe. Nature, 587(7834), 414-419. https://doi.org/10.1038/s41586-020-2902-8
Partovi, F. et al. (2023). Pesticide Residue Fast Screening Using Thermal Desorption Multi-Scheme Chemical Ionization Mass Spectrometry (TD-MION MS) with Selective Chemical Ionization. ACS Omega, 8(29), 25749-25757.
Roper, C. et al. (2019). PM(2.5) Filter Extraction Methods: Implications for Chemical and Toxicological Analyses. Environ Sci Technol, 53(1),434-442.
How to cite: Holm, S., Kontro, J., Lwin, M., Mikkilä, J., Rissanen, M., and Kangasluoma, J.: First measurements with a novel aerosol filter analysis workflow, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19831, https://doi.org/10.5194/egusphere-egu25-19831, 2025.
