title: Electrospray mass spectrometric detection of products and short-lived intermediates in aqueous aerosol microdroplets exposed to a reactive gas.
abstract: The intermediates ISO3- (m/z=207) and IS2O3- (m/z=239) generated in aqueous (NaI/Na2S2O3) microdroplets traversing dilute O3 gas plumes are detected via online electrospray mass spectrometry within approximately 1 ms, and their stabilities gauged by collisionally induced dissociation. The simultaneous detection of anionic reactants and the S2O62-, HSO4-, IO3-, and I3- products as a function of experimental conditions provides evidence of genuinely interfacial reaction kinetics. Although O3(aq) reacts about 3 times faster with I- than with S2O32- in bulk solution, only S2O32- is significantly depleted in the interfacial layers of [I-]/[S2O32-]=10 microdroplets below [O3(g)] approximately 50 ppm.
authors.affiliation: W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: S
authors.initials: S
authors.lastname: Enami
authors.forename: C D
authors.initials: CD
authors.lastname: Vecitis
authors.forename: J
authors.initials: J
authors.lastname: Cheng
authors.forename: M R
authors.initials: MR
authors.lastname: Hoffmann
authors.forename: A J
authors.initials: AJ
authors.lastname: Colussi