title: Applicability of the new 60 μm polyethylene glycol solid-phase microextraction fiber assembly for the simultaneous analysis of six pesticides in water.
abstract: A solid-phase microextraction (SPME) method has been applied for the simultaneous analysis of six pesticides in water, with polar to moderately polar range, by gas chromatography-mass spectrometry (GC-MS). Two types of fiber coatings [60 µm polyethylene glycol (PEG) and 65 µm polydimethylsiloxane/divinylbenzene (PDMS/DVB)] and the effect of salt (addition of 10 and 25% of NaCl) were compared. The extraction efficiency was higher with PEG than with the PDMS/DVB fiber for all pesticides, with the exception of terbuthylazine and phosmet, and with addition of 25% NaCl. The optimized SPME-GC-MS method, adopting the PEG fiber and the addition of 25% NaCl, in addition to other conditions [60 min of direct dipping of the fiber into the water sample (10 mL) under agitation (250 rpm) at ambient temperature; desorption period of 5 min at 240°C] allowed the determination of all studied pesticides and showed good linearity for concentrations ranging from 0.05 to 5 µg/L. Limits of detection varied between 0.003 and 0.145 µg/L, with values below 0.025 µg/L for most of the analytes. Precision ranged from 4.2 to 12%. The proposed method is fast and simple, and was proven to be reliable for the routine analysis of pesticides in water, primarily for environmental monitoring.
authors.affiliation: Centro de Engenharia dos Biossistemas, Instituto Superior de Agronomia, Universidade Técnica de Lisboa, Tapada da Ajuda 1349-017 Lisbon, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Pereira
authors.forename: Emília
authors.initials: E
authors.lastname: Silva
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Cerejeira
mesh_terms: D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D010575:Pesticides / Q000032:analysis / Q000302:isolation & purification*; D011092:Polyethylene Glycols / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D011092:Polyethylene Glycols