Hydroxyl radicals from secondary organic aerosol decomposition in water
Hydroxyl radicals from secondary organic aerosol decomposition in water
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DOI：
10.5194/acp-16-1761-2016
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发表时间：
2015-11
影响因子：
6.3
通讯作者：
Haijie Tong;Andrea M. Arangio;P. Lakey;T. Berkemeier;Fobang Liu;C. Kampf;W. Brune;U. Pöschl;M. Shiraiwa
中科院分区：
文献类型：
--
作者：
Haijie Tong;Andrea M. Arangio;P. Lakey;T. Berkemeier;Fobang Liu;C. Kampf;W. Brune;U. Pöschl;M. Shiraiwa
抽象的。我们发现，环境和实验室产生的二次有机气溶胶(SOA)与液态水相互作用时会形成大量的OH自由基，这可以用有机过氧化氢的分解来解释。以纯水为萃取剂对萜类化合物(α-Pinene、β-Pinene、Lemonene)进行臭氧化反应，生成的摩尔氢产率为∼0.1%，而在Fe2+离子存在下，由于类Fenton反应，摩尔氢产率增加到∼1.5%。在从异戊二烯的光氧化反应中提取SOA样品时，我们还检测到OH的产率约为∼的0.1%，并且随着Fe2+的加入而增加。我们的发现表明，与水和铁相互作用后，SOA颗粒的化学反应活性和老化程度都得到了极大的增强。在黑暗条件下的云滴中，SOA的分解可以与经典的H_2O_2-Fenton反应竞争，成为OH自由基的来源。另外，在人类呼吸道中，吸入和沉积的SOA颗粒可能导致大量的OH自由基的释放，这可能有助于氧化应激，并在大气气溶胶的不利健康影响中发挥重要作用。
Abstract. 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.