Mass Concentrations of Major Acidic Anions in PM10 Particle Fraction in Zagreb Air
This paper presents the results of measurements of major acidic anions chlorides, nitrates, and sulphates in PM10 particle fraction in the city of Zagreb, Croatia.
Sampling was carried out continuously for seven years (21 March 1999 – 20 March 2006). Twenty-four-hour samples of PM10 were collected on cellulose membrane and quartz filters from approximately 100 m3 of ambient air using inertial impactor. Mass concentrations of PM10 fraction were determined by gravimetry. Acidic anions chloride, nitrate and sulphate were analysed using ion chromatography.
The concentration levels of all pollutants showed significant seasonal differences, with values increasing in the winter. The most abundant contributing species to the PM10 mass were sulphates followed by nitrates, and then by chlorides.
We used the mass ratio of (NO3-)/(SO42-) as an indicator of the relative importance of pollutant sources. Results show that the mobile source emission was important contributor to particle mass.
Keywords: air pollution, chlorides, nitrates, sulphates, ion chromatography