Observations of Gas-Phase Alkylamines at a Coastal Site in the East Mediterranean Atmosphere

Abstract

Atmospheric amines are ubiquitous compounds in the atmosphere, having both natural and anthropogenic origin. Recently, they have been identified as important contributors to new particle formation in the atmosphere, but observations of their atmospheric concentrations are scarce. In the present study we introduce the first systematic long-term observations of gas-phase amines measurements in the East Mediterranean atmosphere. Air samples were collected at the Finokalia monitoring station of the University of Crete during a 3.5-year period from January 2013 to July 2016, and analyzed after extraction using a high-performance liquid chromatography triple quadrupole mass spectrometer. The detected alkylamines were the sum of dimethylamine and ethylamine (DMA+EA), trimethylamine (TMA), diethylamine (DEA) and triethylamine (TEA). DMA+EA and TMA were the most abundant alkylamines, with concentrations spanning from the detection limit to 78.0 and 69.8 pptv, and average concentrations of 7.8 ± 12.1 and 7.5 ± 12.4 pptv, respectively. Amines showed pronounced seasonal variability with DMA+EA and TMA concentrations being higher in winter. Statistical analysis of the observations showed different sources for each of the studied amines, except for DMA+ΕA and DEA that appear to have common sources in the region. This analysis points to a marine source of TMA and animal husbandry in the area as a potential source of TEA. None of the alkylamines is correlated with other anthropogenic sources. Furthermore, no clear association was found between the seasonality of NPF events and alkylamines concentrations, while a clear correlation was detected between the seasonality of nucleation mode particle (dp < 25 nm) number concentrations and alkylamine concentrations, indicating that amines may contribute to nucleation mode particles’ production.

Enhancement of Atmospheric Nucleation Precursors on Iodic Acid-Induced Nucleation: Predictive Model and Mechanism

“…The [DEA] > 2.5 × 10 6 cm –3 (0.1 ppt) can reach an enhancement comparable to HIO 2 in IA-induced nucleation. The detected atmospheric [DEA] and [IA] are higher than 2.5 × 10 6 and 10 6 cm –3 , respectively, e.g., in the East Mediterranean 53 and at Mace Head, 14 where the maximum values of [DEA] and [IA] are 9.4 × 10 8 cm –3 (37.5 ppt) and 10 8 cm –3 , respectively. A recent study based on long-term observations found that [IA] can reach about 2.8 × 10 6 cm –3 in the polluted urban atmosphere in Beijing and Nanjing.…”

“…The (IA) 4 (DEA) 3 cluster was set as the boundary cluster and allowed to contribute to the cluster formation rate (see details in the Supporting Information). The [IA] and [DEA] were set to 10 5 , 10 6 , 10 7 , and 10 8 cm –3 , ,, and 2.5 × 10 5 , 2.5 × 10 6 , 2.5 × 10 7 , 2.5 × 10 8 , and 5 × 10 8 cm –3 , − respectively, corresponding to their atmospheric concentration ranges. Similar to a previous study, the setting values of [IA] are the initial concentrations of the IA monomer.…”

Secondary Organic Aerosol Formation from Aqueous Ethylamine Oxidation Mediated by Particulate Nitrate Photolysis

“…Ethylamine (EA) is a volatile organic compound (VOC) that is emitted into the atmosphere from a wide range of sources including animal husbandry, marine organisms, automobiles, sewage, and coal and biomass combustion. − As a VOC, EA contributes to atmospheric particles via new particle formation by acid–base reactions, , gas-phase oxidation product condensation, cloud condensation nuclei (CCN) activity, displacement reaction of ammonium from particles, , and aging of the pre-existing acidic particles . EA is one of the most abundant short-chain aliphatic amines in atmospheric particles, dominant among C1–C3 aliphatic primary amines in PM2.5 with concentrations up to 100 ng/m 3 . ,− …”