TY - JOUR
TI - Secondary organic aerosol markers and related polar organic compounds in summer aerosols from a sub-urban site in Athens: Size distributions, diurnal trends and source apportionment
AU - Kanellopoulos, P.G.
AU - Chrysochou, E.
AU - Koukoulakis, K.
AU - Bakeas, E.
JO - Atmospheric Pollution Research
PY - 2021
VL - 12
TODO - 4
SP - 1-13
PB - Elsevier B.V.
SN - 1309-1042
TODO - 10.1016/j.apr.2021.02.013
TODO - null
TODO - Size-segregated aerosols (six stages with a diameter from <0.49 to >7.2 μm) were collected during daytime and nighttime in the summer of 2020 and were analyzed for dicarboxylic acids, isoprene, α/β-pinene and β-caryophyllene secondary organic aerosol (SOA) tracers, aromatic acids, hydroxy-polyacids, monocarboxylic acids and levoglucosan. The vast majority of the detected compounds presented significantly higher (p < 0.05) concentrations in fine than in coarse modes, excluding benzoic and oleic acids for which the higher fine mode than coarse mode concentrations were not significant and pinonic acid which was found at higher coarse mode concentrations. The dominant compound in the fine mode was 2-methylerythritol (mean of 213 ± 79.4 ng m−3), whereas in coarse particles palmitic acid was the most abundant (mean of 22.8 ± 9.7 ng m−3). All of the detected compounds, except for terephthalic acid, presented higher daytime concentrations, a difference that in the cases of glutaric, suberic, azelaic and pinic acids was significant (p < 0.05). The six-stage size distribution showed various patterns, with most species peaking at particles with a diameter of <1.1 μm suggesting photoxidation sources, while significant peaks at the size of 3–7.2 μm have been observed for suberic, azelaic, pinonic, benzoic, trimellitic and monocarboxylic acids. The hydroscopic growth of particles during nighttime may explain the observed decrease of the fine to coarse concentration ratio. From the employed source apportionment tools four factors where derived explaining 83.0% of total the variance including oxidation of anthropogenic volatile organic compounds (35.6%), oxidation of monoterpenes and sesquiterpenes (21.5%), isoprene's oxidation (14.1%) and photoxidation of unsaturated fatty acids (11.8%). © 2021 Turkish National Committee for Air Pollution Research and Control
ER -