Ion chromatographic and spectrometric determination of water-soluble compounds in airborne particulates, and their correlations in an industrial area in Attica, Greece

Abstract

In the time period from June 2005 to May 2006 in 42 sampling campaigns 84 filter samples of airborne particulate matter, coarse (PM10–2.5) and fine (PM2.5), were collected using a Gent stacked filter unit in the coastal industrial area of Aspropyrgos in Attica, Greece. The average PM10 (PM10–2.5 + PM2.5) concentration was found to be 66 µg · m−3, exceeding more than 1.6 times the annual limit of 40 µg · m−3. The samples were analysed for Cl−, NO3−, SO42−, Ca2+, Mg2+, Na+, K+ and NH4+ using ion chromatography. The data were compared with results obtained with other spectrometric methods, such as inductively coupled plasma-atomic emission spectrometry, atomic absorption spectrometry, energy dispersive X-ray fluorescence and reflectometry. The determined average ionic content comprised about 44% of the PM10 mass. The ionic composition, as well as the possible matrix compounds in both fractions were evaluated by dividing the sampling period into summer and winter season. In the PM10–2.5/PM2.5 fraction in summer time the concentrations of Ca2+, Mg2+ and NO3− were enriched in the coarse fraction. In winter time all species were enriched in the coarse fraction, especially Ca2+, Cl− and NO3−. NH4+ was constantly higher in the fine fraction in summer as well as in winter time. Factor analysis was applied to obtain correlations between cations and anions leading to matrix compounds in both fractions. From the evaluation of the results obtained, some of the local air pollution sources could be identified.