title: Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis.
abstract: Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.
authors.affiliation: EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Julien
authors.affiliation: EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
authors.forename: Pierrick
authors.initials: P
authors.lastname: Nun
authors.affiliation: EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Robins
authors.affiliation: EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
authors.forename: Gérald S
authors.initials: GS
authors.lastname: Remaud
authors.affiliation: Laboratoire Chimie Environnement, University of Aix-Marseille-CNRS FRE 3416 , place Victor Hugo 3, F-13331 Marseille, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Parinet
authors.affiliation: Laboratoire Chimie Environnement, University of Aix-Marseille-CNRS FRE 3416 , place Victor Hugo 3, F-13331 Marseille, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Höhener
mesh_terms: D000096:Acetone / Q000737:chemistry; D002247:Carbon Isotopes / Q000032:analysis* / Q000737:chemistry; D004777:Environment; D005740:Gases; D006536:Heptanes / Q000737:chemistry; D006842:Hydrocarbons, Brominated / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008738:Methyl Ethers / Q000737:chemistry; D008956:Models, Chemical; D008962:Models, Theoretical; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry; D011312:Pressure; D014835:Volatilization
chemical_list: D002247:Carbon Isotopes; D005740:Gases; D006536:Heptanes; D006842:Hydrocarbons, Brominated; D008738:Methyl Ethers; D009930:Organic Chemicals; D000096:Acetone; C028618:n-heptane; C096680:tertiary-amyl methyl ether; C037311:bromoethane; D000432:Methanol