Applying synchrotron radiation-based attenuated total reflection-Fourier transform infrared to evaluate the effects of shipping emissions on fluctuations of PM10-bound organic functional groups and ionic species

The intense light of synchrotron radiation, with the assistance of infrared spectroscopy, allows for the measurement of extremely low levels of organic functional groups. In this study, PM10 samples (n = 84) were collected at three air quality observatory sites strategically situated on the periphery of the seaport, residential zone, and industrial area of Laem Chabang, Thailand from May 27 to June 23, 2020. Aliphatic carbons, carbonyl species, organo-nitrates, aromatic nitro compounds, ammonium ions, carbonate, nitrate ions, sulfate species, and calcium carbonate were successfully characterised in all PM10 samples. Sulfate and aliphatic carbons were the two dominant chemical species detected at all monitoring sites. Sulfate and bisulfate ions were two major ionic species with the percentage contribution of 64%, 74% and 46% to the port area, the urban background and the industrial area, respectively. Aliphatic carbons were the most abundant organic functional groups, contributing 27% and 15% to the industrial area and the port area, respectively. While aliphatic carbons, organo-nitrates, and aromatic nitro compounds were closely related to shipping activities, sea salt aerosols and fertiliser dust can be considered as two potential sources of sulfate and ammonium, respectively. •SR-ATR-FTIR used to chemically characterise PM10 samples from shipping emissions.•Organic compounds linked to shipping activities.•Variation in sulfate concentration is the result of maritime aerosols.•Agricultural fertilisers responsible for variations in ammonium concentrations.