Large differences of highly oxygenated organic molecules (HOMs) and low-volatile species in secondary organic aerosols (SOAs) formed from ozonolysis of β -pinene and limonene

作者：Dandan Liu, Yun Zhang, Shujun Zhong, Shuang Chen, Qiaorong Xie, Donghuan Zhang, Qiang Zhang, Wei Hu, Junjun Deng, Libin Wu, Chao Ma, Haijie Tong, Pingqing Fu · 发表于：Atmospheric chemistry and physics · 年份：2023 · DOI：10.5194/acp-23-8383-2023 · 被引用次数：22 · 研究领域：Atmospheric chemistry and aerosols、Air Quality and Health Impacts、Atmospheric Ozone and Climate

Abstract. Secondary organic aerosols (SOAs) play a key role in climate change and public health. However, the oxidation state and volatility of SOAs are still not well understood. Here, we investigated the highly oxygenated organic molecules (HOMs) in SOAs formed from ozonolysis of β-pinene and limonene. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to characterize HOMs in aerosol filter samples, and a scanning mobility particle sizer (SMPS) was used to measure the concentration and size distribution of SOA particles. The relative abundance of HOMs (i.e., ratio of summed mass spectrometry peak intensity of HOMs to totally identified organic compounds) in limonene SOA was 14 %–20 %, higher than in β-pinene SOA (3 %–13 %), exhibiting different trends with increasing ozone concentrations. β-pinene oxidation-derived HOMs exhibit higher yield at high ozone concentration, accompanied by substantial formation of ultra-low-volatile organic compounds (ULVOCs). Limonene oxidation-derived HOMs exhibit higher yield at moderate ozone concentrations, with semi-, low-, and extremely low-volatile organic compounds (SVOCs, LOVCs, and ELVOCs) play a major role. Combined experimental evidence and theoretical analysis indicate that oxygen-increasing-based peroxy radical chemistry is a plausible mechanism for the formation of oxygenated organic compounds with 10 carbon atoms. Our findings show that HOMs and low-volatile species in β-pinene and limonene SOA are l...