Data handling of GC/MS signals for characterization of PAH sources in Northern Italy aerosols.
The paper describes the characterization of polycyclic aromatic hydrocarbons (PAHs) in atmospheric aerosol samples using Gas Chromatography-Mass Spectrometry analysis. A data handling of GC/MS signals based on Experimental Autocovariance Function (EACVF) is described in order to directly characterize PAHs with a simple and reliable method suitable for processing large batches of samples. The method was successfully applied to 42 aerosol samples collected in different seasons (summer, fall and winter) in two locations in Northern Italy: Milan, a large urban area, and Oasi Le Bine, a rural site. The reliability of the EACVF results was verified by comparison with the values computed with the conventional GC/MS signal treatment and the data of independent studies. Two main emission sources were identified and described by PAH concentration profiles: the road traffic source (TR), characterized by high contributions of FLNT, PYR and CHR, and the residential combustion (COMB) mainly containing pyrogenic high molecular weight PAHs, i.e., CHR, BaP, BeP, BbF and BkF. In addition, some PAH diagnostic ratios were directly computed for the EACVF plot, to distinguish between traffic and combustion dominated emissions, i.e. the ratios CHR/BaP, PYR/BaP and PYR/BeP.
Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara, 17, 44100 Ferrara, Italy. Electronic address: mpc@unife.it.
M C
MC
Pietrogrande
Department of Earth and Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126 Milan, Italy.
M G
MG
Perrone
Department of Earth and Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126 Milan, Italy.
G
G
Sangiorgi
Department of Earth and Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126 Milan, Italy.
L
L
Ferrero
Department of Earth and Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126 Milan, Italy.
E
E
Bolzacchini
D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007558:Italy; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D015203:Reproducibility of Results
D000336:Aerosols; D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons
ACVF; Autocovariance Function; COMB%; COMB% computed with the EACVF method; COMB%(EACF); Data handling; EACVF; GC/MS; GC/MS signal processing; PAHs; PM; Polycyclic aromatic hydrocarbons; Source profiles; TR%; TR% computed with the EACVF method; TR%(EACVF); correlation time between the positions of the digitized chromatogram on which EACVF is computed; experimental autocovariance function computed on the total chromatogram; gas chromatography coupled with mass spectrometry; particle matter; polycyclic aromatic hydrocarbons; relative abundance of PAHs from combustion sources computed with the traditional procedure; relative abundance of PAHs from traffic sources computed with the traditional procedure; Δt