title: A new multi-residue method for analysis of pesticide residues in fruit and vegetables using liquid chromatography with tandem mass spectrometric detection.
abstract: A new multi-residue method for determination of pesticide residues in a wide variety of fruit and vegetables, using the National Food Administration (NFA) ethyl acetate extraction and determination by means of LC-MS/MS, is presented. The method includes pesticides normally detected by LC-UV or LC-fluorescence such as benzimidazoles, carbamates, N-methylcarbamates and organophosphorus compounds with an oxidisable sulphide group as well. After extraction with ethyl acetate, the extract is concentrated and an aliquot of the extract is evaporated to dryness and redissolved in methanol before injection on LC-MS/MS. The method has been validated for 57 different pesticides and metabolites. Representative species from different commodity groups were chosen as matrices in order to study the influence from different matrices on recoveries. The fortification levels studied were 0.01-0.5 mg kg(-1). Matrix effects were tested for all matrices by means of standard addition to blank extracts. The matrix effect, expressed as signal in solvent compared to signal in matrix, was in general found to be small. The obtained recoveries are, with a few exceptions, in the range 70-100%. The proposed method is quick and straightforward and no additional clean-up steps are needed. The method can be used for the analysis of all 57 pesticides in one single determination step at 0.01 mg kg(-1).
authors.affiliation: Research and Development Department, Swedish National Food Administration, PO. Box 622, SE-751 26 Uppsala, Sweden. chja@slv.se
authors.forename: Christer
authors.initials: C
authors.lastname: Jansson
authors.forename: Tuija
authors.initials: T
authors.lastname: Pihlström
authors.forename: Bengt-Göran
authors.initials: BG
authors.lastname: Osterdahl
authors.forename: Karin E
authors.initials: KE
authors.lastname: Markides
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014675:Vegetables / Q000737:chemistry*
chemical_list: D010573:Pesticide Residues