Insights into organic-aerosol sources via a novel laser-desorption/ionization mass spectrometry technique applied to one year of PM<sub>10</sub> samples from nine sites in central Europe

Abstract

Abstract. We assess the benefits of offline laserdesorption/ionization mass spectrometry in understanding ambient particulate matter (PM) sources. The technique was optimized for measuring PM collected on quartz-fiber filters using silver nitrate as an internal standard for m/z calibration. This is the first application of this technique to samples collected at nine sites in central Europe throughout the entire year of 2013 (819 samples). Different PM sources were identified by positive matrix factorization (PMF) including also concomitant measurements (such as NO x , levoglucosan, and temperature). By comparison to reference mass spectral signatures from laboratory wood burning experiments as well as samples from a traffic tunnel, three biomass burning factors and two traffic factors were identified. The wood burning factors could be linked to the burning conditions; the factors related to inefficient burns had a larger impact on air quality in southern Alpine valleys than in northern Switzerland. The traffic factors were identified as primary tailpipe exhaust and most possibly aged/secondary traffic emissions. The latter attribution was supported by radiocarbon analyses of both the organic and elemental carbon. Besides these sources, factors related to secondary organic aerosol were also separated. The contribution of the wood burning emissions based on LDI-PMF (laser-desorption/ionization PMF) correlates well with that based on AMS-PMF (aerosol mass spectrometer PMF) analyses, while the comparison between the two techniques for other components is more complex.

Source Apportionment of Brown Carbon Absorption by Coupling Ultraviolet–Visible Spectroscopy with Aerosol Mass Spectrometry

“…We note that the SOOA MAE λ is higher than that determined in chambers for SOA from O 3 - and OH-initiated oxidation of various biogenic precursors (e.g., limonene and α-pinene). This points to additional unknown sources (e.g., oxidation of fossil precursors , ) or formation mechanisms (e.g., NO 3 -initiated oxidation of terpenes, intraparticle reactions, or interactions between anthropogenic and biogenic emissions) of summertime BrC.…”

Overview of the French Operational Network for In Situ Observation of PM Chemical Composition and Sources in Urban Environments (CARA Program)

“…While allowing for a specific discrimination of the full submicron OA burden, results obtained using such methodologies rarely consider interactions with inorganics and do not trivially link the different OOA fractions to specific SOA precursors and/or formation mechanisms. Advanced data treatment strategies combining OA mass spectra with datasets obtained from complementary co-located measurements could provide further insight into these PM origins (e.g., [120,121]). In particular, adding specific SOA markers to ACSM organic mass spectra proved to allow a better understanding of OA sources during a PM pollution events documented at SIRTA in March 2015.…”

Characterizing the Sources of Ambient PM10 Organic Aerosol in Urban and Rural Catalonia, Spain

“…et al, 2017). Levoglucosan is produced from the pyrolysis of cellulose and is a tracer for biomass-burning sources (Alfarra et al, 2007;Crippa et al, 2013b;Daellenbach et al, 2018;Via et al, 2021;Zotter et al, 2014). BBOA mass spectra exhibited an OM:OC ratio of 2.07 as well as a ƒ 44 :ƒ 60 ratio of 5 with a ƒ 44 value of 0.07, suggesting fresh emission contributions.…”