An integrated analytical approach using ion chromatography, PIXE and electron microscopy to point out the differences in composition of PM 10 individual particles

This study presents a part of a project aiming at characterizing the PM10 composition in the Venice area with detailed chemical analyses using various techniques. The concentrations of six major inorganic ions (Cl-, NO3-, SO42-, Na+, NH4+, Mg2+) and 19 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) were quantified using ion chromatography and PIXE, respectively. The masses of PM10 daily samples and their chemical contents were studied in relationship to micro-meteorological parameters to select a few of them characterized by very different chemical profiles. Four samples from the whole period were categorized as representative of i) clean days; ii) sea spray generation events; iii) high contribution of mineral dust and iv) heavy pollution events. Individual particle analyses of the samples were also performed by SEM-EDS microscopy. Six different classes of particles were identified (mineral particles, chlorides, sulfates, elemental and organic carbon compounds, metals and biological particles) and an estimation of their abundance yielded a significant relationship between the chemical content and composition in individual particles of PM10. Further information was also obtained on PM10 source contributions, morphology, mineralogy and mixed state of particles demonstrating the importance of combining different analytical approaches. © 2013 AIP Publishing LLC