title: Sampling of organophosphorus pesticides at trace levels in the atmosphere using XAD-2 adsorbent and analysis by gas chromatography coupled with nitrogen-phosphorus and ion-trap mass spectrometry detectors.
abstract: This paper shows an analytical methodology based on solid-phase extraction by XAD-2 adsorbent and gas chromatography (GC) coupled with nitrogen-phosphorus (NPD) and ion-trap mass spectrometry detectors (ITMS) in negative chemical ionization (NCI) mode analyses for investigating organophosphorus pesticides (OPs) at trace levels (in nanograms per cubic meter) in the atmosphere: in particular, we set up a procedure for analyzing 38 OPs. For the analytical methodology linearity responses have been obtained in GC-NPD (r > 0.9982) and GC-NCI/ITMS (r > 0.9974) in a large linearity range (0.10-500 pg μL(-1) in both cases) whereas the limits of detection range between 0.01 and 0.03 pg μL(-1) in both the techniques with a relative standard deviation (RSD) below 9.0 in both cases. Particular attention has been devoted to investigate the effect of different solvents (n-hexane, benzene, chloroform, carbon disulfide, acetonitrile) on the OP recovery as well the breakthrough volumes have been evaluated (100% recovery up to 4,286 L g(-1)). The study has also investigated the OP recoveries at different sampling flow rates (1.5 and 2.0 L min(-1)) for determining the optimal conditions for sample collection. Finally, the whole approach has been successfully applied to real samples collected in four different areas in the Molise region (Central Italy) during different seasons: the results show that parathion-ethyl, dimethoate, omethoate, and malathion are present in all periods at low levels (ranging between 70 and 10 ng m(-3)): their levels in such periods can be correlated with spraying as well atmospheric conditions favoring the dispersion/accumulation of these pollutants.
authors: Facoltà di Agraria (DISTAAM), Università degli Studi del Molise, Campobasso, Italy. mvrusso@unimol.it
authors: Mario Vincenzo
authors: MV
authors: Russo
authors: Pasquale
authors: P
authors: Avino
authors: Giuseppe
authors: G
authors: Cinelli
authors: Ivan
authors: I
authors: Notardonato
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000302:isolation & purification*; D001272:Atmosphere / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007558:Italy; D057230:Limit of Detection; D009943:Organophosphorus Compounds / Q000302:isolation & purification*; D010575:Pesticides / Q000302:isolation & purification*; D011137:Polystyrenes / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D000393:Air Pollutants; D009943:Organophosphorus Compounds; D010575:Pesticides; D011137:Polystyrenes; C003771:Amberlite XAD-2 resin