Similarities and Differences in Mass Spectral Signatures of Primary Organic Aerosol From Biomass Burning, Cooking, Coal Combustion, and Vehicle Exhaust

A comprehensive understanding of mass spectra of primary organic aerosols (OA) from anthropogenic sources is crucial for source apportionment of ambient OA measured by aerosol mass spectrometer. However, localized mass spectral data in China are still scarce. This study conducted a series of source emission experiments using a quadrupole aerosol chemical speciation monitor (ACSM) to characterize mass spectra of OA from crop residue burning (CRBOA), wood burning (WBOA), cooking (COA), coal combustion (CCOA), and vehicle exhaust (VEOA). The extracted marker fragments and diagnostic ratios from mass spectra were investigated, revealing their representativeness and effectiveness in distinguishing OA sources. Distinct differences were generally found between OA mass spectra from various anthropogenic sources. Additionally, subtypes of COA and CCOA mass spectra showed notable differences, allowing for finer OA source apportionment. Cluster analysis of existing 57 OA mass spectra further demonstrated their efficacy in identifying OA sources, and revealed certain sources were grouped into distinct clusters. This highlights the importance of using localized mass spectra for refined OA source classification. Our mass spectral characterization of primary OA from anthropogenic sources offers a practical data set for ACSM-based source apportionment, which can support more accurate identification of ambient OA sources in China.