Molecular-Level Insights into the Relationship between Volatility of Organic Aerosol Constituents and PM 2.5 Air Pollution Levels: A Study with Ultrahigh-Resolution Mass Spectrometry

作者：Kai Wang, Yun Zhang, Haijie Tong, Jiajun Han, Pingqing Fu, Ru‐Jin Huang, Hongyan Zhang, Thorsten Hoffmann · 发表于：Environmental Science & Technology · 年份：2024 · DOI：10.1021/acs.est.3c10662 · 被引用次数：18 · 研究领域：Atmospheric chemistry and aerosols、Air Quality and Health Impacts、Air Quality Monitoring and Forecasting

Volatility of organic aerosols (OAs) significantly influences new particle formation and the occurrence of particulate air pollution. However, the relationship between the volatility of OA and the level of particulate air pollution (i.e., particulate matter concentration) is not well understood. In this study, we compared the chemical composition (identified by an ultrahigh-resolution Orbitrap mass spectrometer) and volatility (estimated based on a predeveloped parametrization method) of OAs in urban PM 2.5 (particulate matter with aerodynamic diameter ≤ 2.5 μm) samples from seven German and Chinese cities, where the PM 2.5 concentration ranged from a light (14 μg m –3 ) to heavy (319 μg m –3 ) pollution level. A large fraction (71–98%) of compounds in PM 2.5 samples were attributable to intermediate-volatility organic compounds (IVOCs) and semivolatile organic compounds (SVOCs). The fraction of low-volatility organic compounds (LVOCs) and extremely low-volatility organic compounds (ELVOCs) decreased from clean (28%) to heavily polluted urban regions (2%), while that of IVOCs increased from 34 to 62%. We found that the average peak area-weighted volatility of organic compounds in different cities showed a logarithmic correlation with the average PM 2.5 concentration, indicating that the volatility of urban OAs increases with the increase of air pollution level. Our results provide new insights into the relationship between OA volatility and PM pollution levels and deepen the ...