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Technical University of Crete
Technical University of Crete
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| URI: | http://purl.tuc.gr/dl/dias/8877E400-78CB-46B9-B12C-A2EDC7410325 | ||
| Year | 2009 | ||
| Type of Item | Peer-Reviewed Journal Publication | ||
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| Bibliographic Citation | E. Psillakis, J. Cheng, M. R. Hoffmann and A. Colussi , "Enrichment factors of perfluoroalkyl oxoanions at the air/water interface," J. of Physic. Chem. A, vol. 113, no. 31, pp. 8826-8829, May 2009. doi: 10.1021/jp902795m https://doi.org/10.1021/jp902795m | ||
| Appears in Collections |
The refractory, water-bound perfluoro-n-alkyl carboxylate F(CF2)nCO2- and sulfonate F(CF2)nSO3- surfactantanions reach remote locations by mechanisms that are not well understood. Here we report experiments inwhich the relative concentrations of these anions on the surface of microdroplets produced by nebulizingtheir aqueous solutions are measured via electrospray ionization mass spectrometry. Enrichment factors f(relative to Br-: f(Br-) ≡ 1) increase with n, asymptotically reaching f[F(CF2)nSO3-] ∼ 2 f[F(CF2)nCO2-] ∼200 f(Br-) values above n ∼ 8. The larger f values for F(CF2)nSO3- over their F(CF2)nCO2- congeners areconsistent with a closer approach of the bulkier, less hydrated -SO3- headgroup to the air/water interface.A hyperbolic, rather than the predicted linear log f[F(CF2)nCO2-] vs n dependence suggests the onset ofconformational restrictions to interfacial enrichment above n ∼ 4. Marine aerosols produced from contaminatedocean surface waters are therefore expected to be highly enriched in F(CF2)nCO2-/F(CF2)nSO3- species.
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