Experimental Study of the Formation of Organosulfates from α-Pinene Oxidation. Part I: Product Identification, Formation Mechanisms and Effect of Relative Humidity.
In the present study, quasi-static reactor and atmospheric simulation chamber experiments were performed to investigate the formation of α-pinene-derived organosulfates. Organosulfates (R-OSO3H) were examined for the reactions between acidified ammonium sulfate particles exposed to an individual gaseous volatile organic compound, such as α-pinene and oxidized products (α-pinene oxide, isopinocampheol, pinanediol and myrtenal). Molecular structures were elucidated by liquid chromatography interfaced to high-resolution quadrupole time-of-flight mass spectrometry equipped with electrospray ionization (LC/ESI-HR-QTOFMS). New organosulfate products were detected and identified for the first time in the present study. Reaction with α-pinene oxide was found to be a favored pathway for organosulfate formation (C10H18O5S) and to yield organosulfate dimers (C20H34O6S and C20H34O9S2) and trimers (C30H50O10S2) under dry conditions (RH < 1%) and high particle acidity and precursor concentrations (1 ppm). The role of relative humidity on organosulfate formation yields and product distribution was specifically examined. Organosulfate concentrations were found to decrease with increasing relative humidity. Mechanistic pathways for organosulfate formation from the reactions between α-pinene, α-pinene oxide, isopinocampheol, or pinanediol with acidified ammonium sulfate particles are proposed.
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Duporté
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Flaud
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Geneste
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Augagneur
Université Paris-Est-Créteil (UPEC) and Université Paris Diderot (UPD), LISA, UMR 7583 , F-94010 Créteil, France.
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Pangui
Université Paris-Est-Créteil (UPEC) and Université Paris Diderot (UPD), LISA, UMR 7583 , F-94010 Créteil, France.
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Lamkaddam
Université Paris-Est-Créteil (UPEC) and Université Paris Diderot (UPD), LISA, UMR 7583 , F-94010 Créteil, France.
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Gratien
Université Paris-Est-Créteil (UPEC) and Université Paris Diderot (UPD), LISA, UMR 7583 , F-94010 Créteil, France.
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Doussin
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Budzinski
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Villenave
Université de Bordeaux, EPOC, UMR 5805 , F-33405 Talence Cedex, France.|CNRS, EPOC, UMR 5805 , F-33405 Talence Cedex, France.
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Perraudin