Simultaneous Detection of Alkylamines in the Surface Ocean and Atmosphere of the Antarctic Sympagic Environment

Dall'Osto, M.; Airs, R. L.; Beale, R.; Cree, C.; Fitzsimons, M. F.; Beddows, D.; Harrison, R. M.; Ceburnis, D.; O'Dowd, C.; Rinaldi, M.; Paglione, M.; Nenes, A.; Decesari, S.; Simo, R.
Acs Earth and Space Chemistry
Measurements of alkylamines from seawater and atmospheric samples collected simultaneously across the Antarctic Peninsula, South Orkney and South Georgia Islands are reported. Concentrations of mono-, di-, and trimethylamine (MMA, DMA, and TMA, respectively), and their precursors, the quarternary amines glycine betaine and choline, were enhanced in sympagic seawater samples relative to ice-devoid pelagic ones, suggesting the microbiota of sea ice and sea ice-influenced ocean is a major source of these compounds. Primary sea-spray aerosol particles artificially generated by bubbling seawater samples were investigated by aerosol time-of-flight mass spectrometry (ATOFMS) of single particles; their mixing state indicated that alkylamines were aerosolized with sea spray from dissolved and particulate organic nitrogen pools. Despite this unequivocal sea spray-associated source of alkylamines, ATOFMS analyses of ambient aerosols in the sympagic region indicated that the majority (75-89%) of aerosol alkylamines were of secondary origin, that is, incorporated into the aerosol after gaseous air-sea exchange. These findings show that sympagic seawater properties are a source of alkylamines influencing the biogenic aerosol fluxed from the ocean into the boundary layer; these organic nitrogen compounds should be considered when assessing secondary aerosol formation processes in Antarctica.
ATOFMS,Chemistry,Geochemistry and Geophysics,Polar biogeochemistry,Polar ecology,Secondary Aerosols,Southern Ocean,boundary-layer,chemical-characterization,cloud condensation nuclei,concordia site,containing particles,marine aerosol,mass-spectrometry,mixi
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