Comparative analysis of organic chemical compositions in airborne particulate matter from Ulaanbaatar, Beijing, and Seoul using UPLC-FT-ICR-MS and artificial neural network

• Published in: The Science of the total environment 2023-11, Vol.901, p.165917-165917, Article 165917
• Main Authors: Son, Seungwoo, Park, Moonhee, Jang, Kyoung-Soon, Lee, Ji Yi, Wu, Zhijun, Natsagdorj, Amgalan, Kim, Young Hwan, Kim, Sunghwan
• Format: Article
• Language: English
• Subjects: Airborne particulate matter; Artificial neural network; FT-ICR MS; GCxGC/HRMS; Organo‑nitrogen; Organo‑sulfur
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.165917

This paper presents comparative study on the composition and sources of PM2.5 in Ulaanbaatar, Beijing, and Seoul. Ultrahigh performance liquid chromatography (UPLC) combined with ultrahigh resolution mass spectrometry (UHR-MS) were employed to analyze 85 samples collected in winter. The obtained 340 spectra were interpreted with artificial neural network (ANN). PM2.5 mass concentrations in Ulaanbaatar were significantly higher than those in Beijing and Seoul. ANN based interpretation of UPLC UHR-MS data showed that aliphatic/lipid derived organo‑sulfur compounds, polycyclic aromatic and organo‑oxygen compounds were characteristic to Ulaanbaatar. Whereas, aliphatic/lipid-derived organo‑oxygen compounds were major components in Beijing and Seoul. Aromatic organo‑nitrogen compounds were the main contributors to differentiating the spectra obtained from Beijing from the other cities. Based on two-dimensional gas chromatography/high resolution mass spectrometric (GCxGC/HRMS) data, it was determined that the concentrations of the polycyclic aromatic hydrocarbon (PAH) and polycyclic aromatic sulfur heterocycle (PASH) containing sulfur were highest in Ulaanbaatar, followed by Beijing and Seoul. Coal/biomass combustion was identified as the primary source of contamination in Ulaanbaatar, while petroleum combustion was the main contributor to PM2.5 in Beijing and Seoul. The conclusion that diesel-powered heavy-duty trucks and buses are the main contributors to NOx emissions in Beijing is consistent with previous reports. This study provides a more comprehensive understanding of the composition and sources of PM2.5 in the three cities, with a focus on the differences in their atmospheric pollution profiles based on the UPLC UHR-MS and ANN analysis. It is notable that this study is the first to utilize this method on a large-scale sample set, providing a more detailed and molecular-level understanding of the compositional differences among PM2.5. Overall, the study contributes to a better understanding of the sources and composition of PM2.5 in Northeast Asia, which is essential for developing effective strategies to reduce air pollution and improve public health. [Display omitted] •85 PM2.5 samples from three mega cities studied with UPLC UHR-MS and ANN.•Aliphatic SOx and condensed aromatic compounds observed in Ulaanbaatar•Coal burning was primary source for PM2.5 at Ulaanbaatar.•Aliphatic or lipid type oxygenated compounds abundant in PM2.5 at Beijing and Seoul•NOx