Volume 13, No. 1, February 2013, Pages 137-147 PDF(616 KB)
Comparing the Performance of Teflon and Quartz Membrane Filters Collecting Atmospheric PM: Influence of Atmospheric Water
Cinzia Perrino1, Silvia Canepari2, Maria Catrambone1
1 C.N.R. Institute of Atmospheric Pollution Research, Via Salaria, Km 29,300, Monterotondo St. (Rome), 00015, Italy
2 Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro, 5, Rome, 00185, Italy
Mass concentration and chemical composition of PM10 and PM2.5 was measured during eight one-month winter and summer field studies carried out in the Po Valley (Northern Italy). PM was daily collected on Teflon (T) and on quartz (Q) filters set side-by-side. During the summer periods the differences between the mass concentrations measured on the two filters (T-Q) were within the range of experimental error, while statistically significant positive differences were detected during the winter periods. The sum of the chemical analyses (elements, ions, elemental and organic carbon) allowed the achievement of satisfactory mass closure during the summer periods, while unaccounted masses of the order of 10–20% of the PM mass measured on Teflon were detected during the winter periods. Unaccounted mass and T-Q differences increased during periods of high atmospheric stability, when the ammonium nitrate concentration also increased rapidly. Unaccounted masses and T-Q differences can be attributed to PM-bound and PM-adsorbed water.
Aerosol sampling; Filters; Chemical characterisation; Mass closure; Water content.