title: Multi-residue method for the determination of organochlorine pesticides in fish feed based on a cleanup approach followed by gas chromatography-triple quadrupole tandem mass spectrometry.
abstract: A multi-residue method for the determination of organochlorine pesticides in fish feed samples was developed and optimized. The method is based on a cleanup step of the extracted fat, carried out by liquid-liquid extraction on diatomaceous earth cartridge with n-hexane/acetonitrile (80/20, v/v) followed by solid phase extraction (SPE) with silica gel-SCX cartridge, before the identification and quantification of the residues by gas chromatography-triple quadrupole tandem spectrometry (GC-MS/MS). Performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), for each pesticide were determined. Instrumental LODs ranged from 0.01 to 0.11 microg L(-1), LOQs were in the range of 0.02-0.35 microg L(-1), and calibration curves were linear (r2>0.999) in the whole range of explored concentrations (5-100 microg L(-1)). Repeatability values were in the range of 3-15%, evaluated from the relative standard deviation of six samples spiked at 100 microg kg(-1) of fat, and in compliance with that derived by the Horwitz's equation. No matrix effects or interfering substances were observed in fish feed analyses. The proposed method allowed high recoveries (92-116%) of spiked extracted fat samples at 100 microg kg(-1), and very low LODs (between 0.02 and 0.63 microg kg(-1)) and LOQs (between 0.05 and 2.09 microg kg(-1)) determined in fish feed samples.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, via Manfredonia 20, 71100 Foggia, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Nardelli
authors.forename: Daniela
authors.initials: D
authors.lastname: dell'Oro
authors.forename: Carmen
authors.initials: C
authors.lastname: Palermo
authors.forename: Diego
authors.initials: D
authors.lastname: Centonze
mesh_terms: D000818:Animals; D005399:Fishes; D005506:Food Contamination / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D057230:Limit of Detection; D010573:Pesticide Residues / Q000032:analysis*; D017747:Seafood / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010573:Pesticide Residues