engleski

Elemental and Organic Carbon in PM2.5 at a Coastal Urban Background Station in Croatia

Mass concentrations of elemental (EC) and organic carbon (OC) in particulate matters with an equivalent aerodynamic diameter less than 2.5 µm (PM2.5) were investigated in 2017 and 2018 during cold (January to March) and warm (July to September) periods of the year. Sampling was conducted at a coastal urban background station located in Rijeka, Croatia. PM2.5 samples were collected during 24-hour periods from approximately 55 m3 of ambient air on quartz fibre filters (Pall, 47 mm) pre-fired at 900°C for 3 hours. Mass concentrations of PM2.5 were determined gravimetrically according to the standard EN 12341:2014. Carbon content was measured by the thermal-optical transmittance method (TOT) using a carbon analyser with a flame ionization detector operating according to a NIOSH-like temperature program. In 2018, there were slight differences in the average mass concentrations of PM2.5 between the cold and warm periods, which was unexpected compared to previous measurements, while in 2017 the average mass concentrations of PM2.5 were statistically higher during the cold period. The average mass concentrations of OC and EC were higher in the cold than during the warm period. The average OC/EC mass ratio values of around 7, observed at a coastal urban background station in Rijeka, point to the influence of secondary organic aerosols.

EC, OC, PM2.5, Rijeka, OC/EC ratio

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