Characterization of Polar Organosulfates in Secondary Organic Aerosol from the Green Leaf Volatile 3-Z-Hexenal

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• 作者：Mohammad Safi Shalamzari ; Ariane Kahnt ; Reinhilde Vermeylen ; Tadeusz E. Kleindienst ; Michael Lewandowski ; Filip Cuyckens ; Willy Maenhaut ; Magda Claeys
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：November 4, 2014
• 年：2014
• 卷：48
• 期：21
• 页码：12671-12678
• 全文大小：432K
• ISSN：1520-5851

文摘

Evidence is provided that the green leaf volatile 3-Z-hexenal serves as a precursor for biogenic secondary organic aerosol through the formation of polar organosulfates (OSs) with molecular weight (MW) 226. The MW 226 C₆鈥揙Ss were chemically elucidated, along with structurally similar MW 212 C₅鈥揙Ss, whose biogenic precursor is likely related to 3-Z-hexenal but still remains unknown. The MW 226 and 212 OSs have a substantial abundance in ambient fine aerosol from K-puszta, Hungary, which is comparable to that of the isoprene-related MW 216 OSs, known to be formed through sulfation of C₅-epoxydiols, second-generation gas-phase photooxidation products of isoprene. Using detailed interpretation of negative-ion electrospray ionization mass spectral data, the MW 226 compounds are assigned to isomeric sulfate esters of 3,4-dihydroxyhex-5-enoic acid with the sulfate group located at the C-3 or C-4 position. Two MW 212 compounds present in ambient fine aerosol are attributed to isomeric sulfate esters of 2,3-dihydroxypent-4-enoic acid, of which two are sulfated at C-3 and one is sulfated at C-2. The formation of the MW 226 OSs is tentatively explained through photooxidation of 3-Z-hexenal in the gas phase, resulting in an alkoxy radical, followed by a rearrangement and subsequent sulfation of the epoxy group in the particle phase.