Particulate matter (PM) is produced by a variety of anthropogenic as well as natural processes and is a particularly important research topic due to their detrimental impacts on human health. We present here investigations on the photoaging of these PM in the aqueous phase and particularly on the effects of hydroxyl radical (<sup>●</sup>OH) production, which is one of the major species driving to the photoaging of the PM.  A sampling campaign from an urban, a rural and a mixed urban-rural site was done in the Denver area, Colorado. Following collection, part of the samples was extracted into water and photoaged using simulated sunlight. The optical properties and the potential of the PM aqueous extracts to generate <sup>●</sup>OH were measured, it was observed that the light absorbance capacity was higher in the urban site than in the rural one and that the decrease in light absorbance properties during photoirradiation was correlated with the iron and the nitrate content of the extracts. These observations correspond to a scenario where the PM are mostly produced in the urban site and are transported to the rural one, with a mean age of the PM higher in the rural site.  This work should help to understand the parameters that influence the photoaging of PM in the atmosphere, as well as the influence of trace elements on this process.

Photoaging of atmospheric particulate matter in the aqueous phase

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.