Organic nitrogen in rain and aerosol at Cape Grim, Tasmania, Australia

Abstract

During the Southern Hemispheric spring of 2000 (during the months of November and early December), rain, bulk and size‐separated aerosol samples were collected at the Cape Grim Baseline Air Pollution Station located on the island of Tasmania, Australia and analyzed for total organic nitrogen (N), urea, and dissolved free amino acids. Rain and bulk aerosol samples contained organic N at concentrations representing, on average, between 19 and 25% of total N. Urea was not detected in the six rain samples analyzed. However, urea represented ∼24% of the organic N contained in nonbaseline aerosol samples, and ∼2% of the organic N contained within baseline samples. Trajectory analysis combined with meteorological data indicated that high concentrations of urea within aerosols were mainly due to Tasmanian sources, likely animal emissions, although the application of urea fertilizers cannot be dismissed as a source. In nonbaseline samples the highest concentrations of urea were associated with the coarse mode aerosol (>1 μm), although urea was also found in the fine mode aerosol (<1 μm), potentially indicating gas‐to‐particle conversion of urea. Aerosol samples collected in marine air masses contained urea within an intermediate fraction centered at ∼1 μm suggesting the sea surface microlayer as a source. Dissolved free amino acids contributed ∼53% of the organic N in rain, but were not a significant proportion of the total organic N fraction in either nonbaseline or baseline aerosol samples. Due to their presence in rain, amino acids likely exist in aerosols as unhydrolyzed proteins. In cascade impactor samples highly influenced by marine sources, profiles for amino N were inversely related to urea N, possibly indicating live species and the sea surface microlayer as a source for organic N.

Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere

“…The sharply enhanced WSON in Xi'an and the above documented phenomena can be explained by an increased deposition of volatile alkylamines onto dust particles via adsorption and/or heterogeneous reaction (Mace et al, 2003a;Qiu et al, 2011). In addition, the coarse mode of WSON may also be directly originated from biological organisms in Gobi dust, which contains a certain amount of WSON species (Mace et al, 2003a).…”

Five primary sources of organic aerosols in the urban atmosphere of Belgrade (Serbia)

“…Indeed, peptidoglycan in microbial cellular walls contains a high proportion of D-Ala, D-Asp, D-Glu and D-Ser (Dittmar et al, 2001;McCarthy et al, 1998). Due to their low volatility, AAs have been observed in condensed phases such as particulate matter (Barbaro et al, 2011;Barbaro et al, 2015;Di Filippo et al, 2014;Matsumoto and Uematsu, 2005;Scalabrin et al, 2012), dew (Scheller, 2001), rain (Mace et al, 2003b;Mace et al, 2003c), fog (Zhang and Anastasio, 2003), microlayer (Kuznetsova et al, 2004;Matrai et al, 2008), lakes (Barbaro et al, 2014) and marine waters (Kuznetsova et al, 2004;Matrai et al, 2008;Sommerville and Preston, 2001).…”

“…In urban environments, the literature reports atmospheric concentrations of L-FAAs ranging between 334 and 2470 pmol m −3 (Barbaro et al, 2011;Di Filippo et al, 2014;Yang et al, 2005;Zhang and Anastasio, 2003). In marine and marine remote aerosols, lower levels ranging from 1.5 to 648 pmol m −3 were observed (Barbaro et al, 2015;Mace et al, 2003b;Mace et al, 2003c;Matsumoto and Uematsu, 2005;Wedyan and Preston, 2008). At a Polar coastal site in the Arctic (Ny Alesund, Svalbard Islands) (Scalabrin et al, 2012), during the summer, FAAs ranged from 0.59 to 4.7 pmol m −3…”

The role of air-sea exchange in the marine nitrogen cycle

“…In both remote and more contaminated areas the organic nitrogen has an important fine mode aerosol component suggesting it is formed from gas to particle reactions, although a coarse mode from primary sources is also seen. (Cornell et al, 2001;Mace et al, 2003c;Russell et al, 2003). Seitzinger and Sanders (1999) have suggested that a significant fraction of atmospheric organic nitrogen may be bioavailable.…”