Water-soluble organic compounds (WSOCs) are an important group of chemical tracers that may give relevant information on the relative strengths of primary emission sources and secondary photochemical processes on air quality. In fact, they can be primarily emitted into the atmosphere by a multiplicity of sources -- including power plants, vehicular circulation, meat cooking operations and biomass burning -- or secondarily produced by photochemical atmosphere reactions from both biogenic and anthropogenic precursors. This paper describes the development of a GC-MS procedure for the simultaneous analysis of several WSOCs with a wide range of water solubility, including carboxylic acids and sugars. The response surface methodology (RSM) including central composite design (CCD) was applied to optimize solvent extraction: the factors considered were the solvent type (characterized by p’ parameter ) and volume (10-20 ml). On the basis of RSM, the optimum extraction solvent was a mixture of metane:dichlorometane (90:10) using a volume of 10 ml. To validate the optimized conditions, a comparative study was performed towards the aqueous extraction, as reference solvent for water-soluble components, for blank filters spiked with standard solutions of WSOCs, and real PM samples. The optimized procedure provides the low detection limits (≤2 ngm-3) and the good reproducibility (RSD%≤13%) required by environmental monitoring of chemical markers of atmospheric processes.
MULTIANALYTICAL GC-MS METHOD OF WATER SOLUBLE COMPOUNDS IN ATMOSPHERIC AEROSOL
PIETROGRANDE, Maria Chiara;BACCO, Dimitri;NASSI, Marianna;VISENTIN, Marco
2012
Abstract
Water-soluble organic compounds (WSOCs) are an important group of chemical tracers that may give relevant information on the relative strengths of primary emission sources and secondary photochemical processes on air quality. In fact, they can be primarily emitted into the atmosphere by a multiplicity of sources -- including power plants, vehicular circulation, meat cooking operations and biomass burning -- or secondarily produced by photochemical atmosphere reactions from both biogenic and anthropogenic precursors. This paper describes the development of a GC-MS procedure for the simultaneous analysis of several WSOCs with a wide range of water solubility, including carboxylic acids and sugars. The response surface methodology (RSM) including central composite design (CCD) was applied to optimize solvent extraction: the factors considered were the solvent type (characterized by p’ parameter ) and volume (10-20 ml). On the basis of RSM, the optimum extraction solvent was a mixture of metane:dichlorometane (90:10) using a volume of 10 ml. To validate the optimized conditions, a comparative study was performed towards the aqueous extraction, as reference solvent for water-soluble components, for blank filters spiked with standard solutions of WSOCs, and real PM samples. The optimized procedure provides the low detection limits (≤2 ngm-3) and the good reproducibility (RSD%≤13%) required by environmental monitoring of chemical markers of atmospheric processes.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
