Critical contribution of chemically diverse carbonyl molecules to the oxidative potential of atmospheric aerosols

Abstract

Abstract. Carbonyls have an important effect on atmospheric chemistry and human health because of their high electrophilicity. Here, high-throughput screening of carbonyl molecules in complex aerosol samples was achieved by combining targeted derivatization with non-targeted analysis using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Results showed that water-soluble organic matter (WSOM) in PM2.5 contains a large variety of carbonyls (5147 in total), accounting for 17.6 % of all identified organic molecules. Compared with non-carbonyl molecules, carbonyl molecules are more abundant in winter than in summer, and have unique molecular composition and chemical parameters. For the first time, a significant positive correlation was found between the abundance of carbonyl molecules and the dithiothreitol (DTT) activities of WSOM, and the elimination of the carbonyl group remarkably reduced the DTT activities, highlighting the pivotal role of carbonyls in determining the oxidative potential (OP) of organic aerosol. Among various molecules, oxidized aromatic compounds containing the carbonyl group produced in winter contributed more to the enhancement of DTT activity, which could be used as potential markers of atmospheric oxidative stress. This study improves our understanding of the chemical diversity and environmental health effects of atmospheric carbonyls, emphasizing the need for targeted strategies to mitigate the health risks associated with carbonyl-rich aerosols.

Modelling molecular composition of SOA from toluene photo-oxidation at urban and street scales

“…3. Considering the toxicity of hydroperoxide and carbonyls due to their inuences on oxidative potential, 23,26 the functional group distribution of the various compounds suggests notable health impacts of the compounds simulated with rdc. Mech.…”

“…22 Furthermore, they account for the great variety of molecules and their different functional groups, which may be of particular interest to better understand the impact of SOA on human health. For example, the decomposition of organic hydroperoxides, 23,24 peracids, 25 and carbonyls 26 can lead to the formation of ROS. 27 Toluene SOA may also affect ROS formation via the redox cycling of quinoid compounds.…”