title: Investigation of the photochemical behaviour of pyrethroids lacking the cyclopropane ring by photo-solid-phase microextraction and gas chromatography/mass spectrometry.
abstract: The characterization of by-products arising from the UV photodegradation of two insecticide pyrethroids lacking the cyclopropane ring (flucythrinate and fenvalerate) has been investigated by gas chromatography coupled with mass spectrometry (GC/MS). Twenty photoproducts were tentatively identified mainly based on the interpretation of the experimental mass spectra or by using reference mass spectra. Some of these compounds had not previously been detected. Furthermore, the generation of some of the photoproducts might be a matter for concern due to their potential toxicity. The corresponding photodegradation routes, including postulation of the intermediate radicals, have also been proposed. These photodegradation studies were performed by photo-solid-phase microextraction (photo-SPME) in which the SPME fibre was exposed to light after extraction of the target analytes from aqueous solutions. The degradation kinetics of the investigated pyrethroids and the photoformation-photodegradation curves of the photoproducts generated in situ were also monitored through the ion chromatograms obtained for different irradiation times and the corresponding mass spectra.
authors.affiliation: Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Campus Sur, Universidad de Santiago de Compostela, E-15706 Santiago de Compostela, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Fernandez-Alvarez
authors.forename: Maria
authors.initials: M
authors.lastname: Llompart
authors.forename: Carmen
authors.initials: C
authors.lastname: Garcia-Jares
authors.forename: Thierry
authors.initials: T
authors.lastname: Dagnac
authors.forename: Marta
authors.initials: M
authors.lastname: Lores
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007306:Insecticides / Q000737:chemistry; D007700:Kinetics; D009570:Nitriles / Q000737:chemistry*; D010648:Phenylacetates / Q000737:chemistry*; D010782:Photolysis; D011722:Pyrethrins / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods*; D013997:Time Factors
chemical_list: D007306:Insecticides; D009570:Nitriles; D010648:Phenylacetates; D011722:Pyrethrins; C027975:flucythrinate; C017690:fenvalerate