Hydroxyl radicals from secondary organic aerosol decomposition in water
Item
Title (Dublin Core)
Hydroxyl radicals from secondary organic aerosol decomposition in water
Description (Dublin Core)
We found that ambient and laboratory-generated secondary organic aerosols (SOA) form substantial amounts of OH radicals upon interaction with liquid water, which can be explained by the decomposition of organic hydroperoxides. The molar OH yield from SOA formed by ozonolysis of terpenes (<i>α</i>-pinene, <i>β</i>-pinene, limonene) is ∼ 0.1 % upon extraction with pure water and increases to ∼ 1.5 % in the presence of Fe<sup>2+</sup> ions due to Fenton-like reactions. Upon extraction of SOA samples from OH photooxidation of isoprene, we also detected OH yields of around ∼ 0.1 %, which increases upon addition of Fe<sup>2+</sup>. Our findings imply that the chemical reactivity and aging of SOA particles is strongly enhanced upon interaction with water and iron. In cloud droplets under dark conditions, SOA decomposition can compete with the classical H<sub>2</sub>O<sub>2</sub> Fenton reaction as the source of OH radicals. Also in the human respiratory tract, the inhalation and deposition of SOA particles may lead to a substantial release of OH radicals, which may contribute to oxidative stress and play an important role in the adverse health effects of atmospheric aerosols.
Creator (Dublin Core)
Tong, Haijie
Arangio, Andrea M.
Lakey, Pascale S. J.
Berkemeier, Thomas
Liu, Fobang
Kampf, Christopher J.
Brune, William H.
Pöschl, Ulrich
Shiraiwa, Manabu
Date (Dublin Core)
2018-09-10
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-16-1761-2016
https://acp.copernicus.org/articles/16/1761/2016/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
