Résumé
In the present study, quasi-static reactor and atmospheric simulation-chamber experiments were performed to investigate the. forination of alpha-pirrene-derived organo-sulfates. OrganosulfateS (R-OSO3H) were examined for the reactions between acidified ammonium sulfate particles exposed to an individual gaseous volatile organic compound, such as alpha-pinene and oxidized-products (alpha-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 electrospthy ionization (LC/ESI-HR-QTOFMS). New organosulfate products, were detected and identified for the first time in the present study: Reaction with alpha-pinerie oxide was found to lie alpha-favored pathway for organosulfate formation (C10H18O5S) and to yield organosulfate dimers (C20H34O6S and C20H34O9S2,) and turners (C30H50O10S2) Under dry conditions (RH < 1%) and high particle acidity and precursor concentrations (1 ppm). The role of relative humidity on organosulfate formation yields land product distribution was specifically examined. Organosulfate concentrations were, found to decrease with increasing relative humidity. Mechanistic pathways for organosulfate formation from the reactions between a-pinene, a-pinene oxide, isopinocampheol, or pinanediol with acidified ammonium sulfate particles are proposed: