TY - JOUR
T1 - Hydroxyl radicals from secondary organic aerosol decomposition in water
AU - Tong, Haijie
AU - Arangio, Andrea M.
AU - Lakey, Pascale S.J.
AU - Berkemeier, Thomas
AU - Liu, Fobang
AU - Kampf, Christopher J.
AU - Brune, William H.
AU - Poschl, Ulrich
AU - Shiraiwa, Manabu
N1 - Publisher Copyright:
© 2016 Author(s).
PY - 2016/2/15
Y1 - 2016/2/15
N2 - 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 (α-pinene, β-pinene, limonene) is ∼0.1% upon extraction with pure water and increases to ∼1.5% in the presence of Fe2+ 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 Fe2+. 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 H2O2 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.
AB - 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 (α-pinene, β-pinene, limonene) is ∼0.1% upon extraction with pure water and increases to ∼1.5% in the presence of Fe2+ 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 Fe2+. 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 H2O2 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.
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U2 - 10.5194/acp-16-1761-2016
DO - 10.5194/acp-16-1761-2016
M3 - Article
AN - SCOPUS:84958279755
SN - 1680-7316
VL - 16
SP - 1761
EP - 1771
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 3
ER -