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

• Published in: ACS Earth and Space Chemistry
• Main Authors: Dall’Osto, M, Airs, RL, Beale, R, Cree, Charlotte, Fitzsimons, Mark, Beddows, D, Harrison, RM, Ceburnis, D, O’Dowd, C, Rinaldi, M, Paglione, M, Nenes, A, Decesari, S, Simó, R
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Chemical Society 2019
• Subjects: Polar biogeochemistry; marine aerosol; ATOFMS; Secondary Aerosols; Southern Ocean; polar emissions; Polar ecology; Antarctic; Antarctic Peninsula; The Antarctic; Antarc*; Antarctica; Sea ice
• Online Access: http://hdl.handle.net/10026.1/13697; https://doi.org/10.1021/acsearthspacechem.9b00028

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 sea water 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, i.e., 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.