title: Comparative study of sample preparation procedures to determine fipronil in pollen by gas chromatography with mass spectrometric and electron-capture detection.
abstract: Several sample preparation methods have been assayed to analyze residues of fipronil in pollen at trace concentrations. Extraction with organic solvents, solid-phase extraction on either commercial cartridges or a Florisil-packed column and a matrix solid-phase dispersion, also with Florisil as a dispersing agent, have been tested. Determination of fipronil in the extracts has been carried out by GC with electron-capture and mass spectrometric detection. An extraction with acetonitrile followed by a clean-up on ODS or polymeric cartridges was the most suitable procedure to obtain acceptable recoveries and relatively simple chromatograms. The matrix-effects observed in the quantification can be corrected with a matrix-matched calibration.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Valladolid, Prado de la Magdalena s/n, 47005 Valladolid, Spain. jjimenez@qa.uva.es
authors.forename: J J
authors.initials: JJ
authors.lastname: Jiménez
authors.forename: J L
authors.initials: JL
authors.lastname: Bernal
authors.forename: M J
authors.initials: MJ
authors.lastname: del Nozal
authors.forename: Maria T
authors.initials: MT
authors.lastname: Martín
authors.forename: R
authors.initials: R
authors.lastname: Mayo
mesh_terms: D002138:Calibration; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D011058:Pollen / Q000737:chemistry*; D011720:Pyrazoles / Q000032:analysis*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods; D012997:Solvents / Q000737:chemistry
chemical_list: D011720:Pyrazoles; D012997:Solvents; C082360:fipronil