title: Evaluation of large volume-difficult matrix introduction-gas chromatography-time of flight-mass spectrometry (LV-DMI-GC-TOF-MS) for the determination of pesticides in fruit-based baby foods.
abstract: The European Union Baby Food Directive (1999/39/EC), which came into force on 1 July 2002, set legal maximum residue levels at 0.01 mg kg(-1) for all pesticides in baby foods. The combination of large volume-difficult matrix introduction (LV-DMI) with gas chromatography-time of flight-mass spectrometry (GC-TOF-MS), described herein, provides the analyst with a simple but rapid alternative GC-MS technique for the multiresidue analysis of pesticides in fruit-based baby foods. Samples were extracted with ethyl acetate in the presence of Na2SO4 and NaHCO3 and the crude extracts were analysed directly using LV-DMI-GC-TOF-MS. The best overall results (98 pesticides quantified satisfactorily at a spiking level of 0.01 mg kg(-1)) were obtained by analysis of concentrated extracts (2.5 g crop ml(-1)) using a 30-m column, with a chromatographic run time of 25 min. A good signal-to-noise ratio was obtained at the lowest calibrated level (0.0125 microg ml(-1)), with excellent linearity achieved over the range 0.0125-0.25 microg ml(-1) (equivalent to 0.005-0.1 mg kg(-1)). Average recoveries for the analysis of five replicate determinations at a spiking level of 0.01 mg kg(-1) were between 79 and 114% with relative standard derivations generally less than 20%.
authors.affiliation: Central Science Laboratory, Sand Hutton, York YO41 1LZ, UK.
authors.forename: K
authors.initials: K
authors.lastname: Patel
authors.forename: R J
authors.initials: RJ
authors.lastname: Fussell
authors.forename: D M
authors.initials: DM
authors.lastname: Goodall
authors.forename: B J
authors.initials: BJ
authors.lastname: Keely
mesh_terms: D002138:Calibration; D005506:Food Contamination / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000032:analysis; D006581:Hexachlorobenzene / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007225:Infant Food; D063086:Organothiophosphates; D009946:Organothiophosphorus Compounds / Q000032:analysis; D010575:Pesticides / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D005659:Fungicides, Industrial; D063086:Organothiophosphates; D009946:Organothiophosphorus Compounds; D010575:Pesticides; D011722:Pyrethrins; C001182:ethoprop; C017160:cypermethrin; D006581:Hexachlorobenzene; C099952:bifenthrin