Atmospheric chemistry of N-methyl perfluorobutane sulfonamidoethanol, C4F9SO2N(CH3)CH2CH2OH: kinetics and mechanism of reaction with OH.
Relative rate methods were used to measure the gas-phase reaction of N-methyl perfluorobutane sulfonamidoethanol (NMeFBSE) with OH radicals, giving k(OH + NMeFBSE) = (5.8 +/- 0.8) x 10(-12) cm3 molecule(-1) s(-1) in 750 Torr of air diluent at 296 K. The atmospheric lifetime of NMeFBSE is determined by reaction with OH radicals and is approximately 2 days. Degradation products were identified by in situ FTIR spectroscopy and offline GC-MS and LC-MS/MS analysis. The primary carbonyl product C4F9SO2N(CH3)CH2CHO, N-methyl perfluorobutane sulfonamide (C4F9SO2NH(CH3)), perfluorobutanoic acid (C3F7C(O)OH), perfluoropropanoic acid (C2F5C(O)OH), trifluoroacetic acid (CF3C(O)OH), carbonyl fluoride (COF2), and perfluorobutane sulfonic acid (C4F9SO3H) were identified as products. A mechanism involving the addition of OH to the sulfone double bond was proposed to explain the production of perfluorobutane sulfonic acid and perfluorinated carboxylic acids in yields of 1 and 10%, respectively. The gas-phase N-dealkylation product, N-methyl perfluorobutane sulfonamide (NMeFBSA), has an atmospheric lifetime (>20 days) which is much longer than that of the parent compound, NMeFBSE. Accordingly,the production of NMeFBSA exposes a mechanism by which NMeFBSE may contribute to the burden of perfluorinated contamination in remote locations despite its relatively short atmospheric lifetime. Using the atmospheric fate of NMeFBSE as a guide, it appears that anthropogenic production of N-methyl perfluorooctane sulfonamidoethanol (NMeFOSE) contributes to the ubiquity of perfluoroalkyl sulfonate and carboxylate compounds in the environment.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada
Jessica C
JC
D'eon
Michael D
MD
Hurley
Timothy J
TJ
Wallington
Scott A
SA
Mabury
D000393:Air Pollutants; D001272:Atmosphere / Q000737:chemistry*; D005466:Fluorocarbons / Q000032:analysis / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D017550:Spectroscopy, Fourier Transform Infrared; D013449:Sulfonamides / Q000032:analysis / Q000737:chemistry*; D013451:Sulfonic Acids / Q000032:analysis / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000032:analysis / Q000737:chemistry
D000393:Air Pollutants; D005466:Fluorocarbons; C512684:N-methyl perfluorobutane sulfonamidoethanol; D013449:Sulfonamides; D013451:Sulfonic Acids; D017665:Hydroxyl Radical; C033094:perfluorobutyric acid; D014269:Trifluoroacetic Acid; C108042:perfluorobutane