Abstract
Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key com-ponents that affect climate,air quality,and human health.While putative structures have been proposed,the molecular characteristics of EPFRs remain unknown.Here,we report a surrogate method to charac-terize EPFRs in real ambient samples using mass spectrometry.The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons(OxPAH)that interconvert with oxygen-centered EPFR(OC-EPFR).We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse qui-nones,whose diversity is strongly associated with OC-EPFR levels.Both atmospheric oxidation and com-bustion contributed to OC-EPFR formation.Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources.Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs,offering a way to track the development and evolution of aerosol particles in the environment.
基金项目
国家自然科学基金(92143301)
国家自然科学基金(91843301)
国家重点研发计划(2020YFF01014504)
Chinese Academy Sciences Youth Innovation Promotion Association projects()
NETL
NSTL
万方数据