PIXE and ToF-SIMS analysis of streaker samplers filters

This paper presents methodological innovations introduced in the characterisation of urban aerosol collected in Italy in a recent campaign. Two complementary ion beam analysis (IBA) techniques were used to analyse Nuclepore filters used in continuous streaker samplers to collect airborne particles in four Italian towns. Na to Pb elemental concentrations were obtained by particle induced X-ray emission (PIXE), while time of flight secondary ion mass spectrometry (ToF-SIMS) produced, on the same samples, time trends for several elements and molecular fragments. In addition, light attenuation measurements were used as a tracer for black carbon. The data produced by these three techniques was merged into a unique data set to address the characterisation of particulate matter sources. Correlations between elemental concentration trends (PIXE) and relative trends for molecular fragments (ToF-SIMS) and black carbon (light attenuation) have been studied by cluster and principal component analysis

A summertime investigation on urban PM fine and coarse fractions using hourly elemental concentration data series

The summertime composition of particulate matter in the atmosphere of some Italian towns (Florence, Genoa and Milan) has been studied by means of Ion Beam Analysis (IBA) techniques. The aerosol has been collected simultaneously by two-stage continuous streaker samplers, which separate and collect the PM10 particulate matter in two fractions. The hourly concentrations in air of about 20 elements have been extracted in the fine and coarse fractions of PM10 by Particle Induced X-ray (and Gamma-ray) Emission, PIXE (and PIGE) analysis. Absolute Principal Component Factor Analysis (APCFA) has been used to obtain the apportionment of the sources of particulate matter

Elemental characterization of PM10, PM2.5 and PM1 in the town of Genoa (Italy)

The particulate matter (PM) concentration and composition, the PM10, PM2.5, PM1 fractions, were studied in the urban area of Genoa, a coastal town in the northwest of Italy. Two instruments, the continuous monitor TEOM and the sequential sampler PARTISOL, were operated almost continuously on the same site from July 2001 to September 2004. Samples collected by PARTISOL were weighted to obtain PM concentration and then analysed by PIXE (particle induced X-ray emission) and by ED-XRF (energy dispersion X-ray fluorescence), obtaining concentrations for elements from Na to Pb. Some of the filters used in the TEOM microbalance were analysed by ED-XRF to calculate Pb concentration values averaged over 7\u201330 d periods

Characterization of atmospheric aerosols at Monte Cimone, Italy, during summer 2004: Source apportionment and transport mechanisms

Atmospheric aerosols in the PM10 and PM1 fractions have been sampled at the Global Atmospheric Watch station Mount Cimone, Italy (2165 m above mean sea level) for 3 months during summer 2004, and simultaneous size distributions have been derived by means of an optical particle counter. Samples have been analyzed by X-ray fluorescence, ion chromatography, and thermal-optical methodology in order to quantify their elemental, ionic, and carbonaceous constituents. The concentration of PM10 was 16.1 \ub1 9.8 mg m3 (average and standard deviation). Source apportionment allowed us to identify, quantify and characterize the following aerosol classes: anthropogenic pollution (10 mg m3), mineral dust (4 mg m3), and sea salt (0.2 mg m3). Pollution has been further split into ammonium sulfate (44%), organic matter (42%), and other compounds (14%). The nitrate/sulfate ratio in the polluted aerosol was 0.1. Fine particles have been completely related to the polluted aerosol component, and they represented 70% in weight of pollution. Coarse particles characterized the dust and salt components, and crustal oxides have been found to be the largest responsible for the aerosol concentration variations that occurred during the campaign. Nitrate has also been found in the coarse particles, representing 10% of mineral dust. The analysis of the transport mechanisms responsible for aerosol fluctuations permitted us to identify the origin of the major aerosol components: Pollution has been ascribed to regional transport driven by boundary layer meteorology, whereas mineral dust has been related to long-range transport events originating in the Sahara and Sahel. A particularly significant Saharan episode has been identified on 10 August 2004 (PM10 daily concentration, 69.9 mg m3). Average elemental ratios for the African dust events were as follows: Si/Al = 2.31, Fe/Ca = 0.94, Ca/Al = 0.90, K/Ca = 0.44, Ti/Ca = 0.11, and Ti/Fe = 0.12