title: Ultra-performance liquid chromatography for the determination of pesticide residues in foods by tandem quadrupole mass spectrometry with polarity switching.
abstract: An ultra-performance liquid chromatographic (UPLC) electrospray ionisation tandem quadrupole mass spectrometric method has been developed for the determination of 52 pesticides in cereal-based baby foods, oranges and potatoes. The fast polarity switching capability of the mass spectrometer used enabled the determination of 44 of the compounds in the positive ionisation mode and 8 of the compounds in the negative ionisation mode in a single run. Prior to analysis, co-extractives were removed from acetonitrile extracts using dispersive solid-phase extraction with primary secondary amine (50 mg). The UPLC method separates all of the pesticides, resolves structural isomers (e.g. butocarboxim sulfoxide and aldicarb sulfoxide) and has a short (7 min) cycle time. Extracts spiked with pesticides at 0.10 and 0.01 mg kg(-1) yielded average recoveries in the range of 66-124% with relative standard deviations less than 19% for the majority of the analytes.
authors.affiliation: Central Science Laboratory, Sand Hutton, York YO41 1LZ, UK.
authors.forename: Cristiana C
authors.initials: CC
authors.lastname: Leandro
authors.forename: Peter
authors.initials: P
authors.lastname: Hancock
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Fussell
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Keely
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010573:Pesticide Residues