title: Multiclass method for the determination of 62 antibiotics in milk.
abstract: A multiclass method for screening and confirmatory analysis of antimicrobial residues in milk has been developed and validated. Sixty-two antibiotics belonging to ten different drug families (amphenicols, cephalosporins, lincosamides, macrolides, penicillin, pleuromutilins, quinolones, rifamycins, sulfonamides and tetracyclines) have been included. After the addition of an aqueous solution of EDTA, the milk samples were extracted twice with acetonitrile, evaporated and dissolved in ammonium acetate. After centrifugation, 10 µl were analysed using LC-Q-Orbitrap operating in positive electrospray ionization mode. The method was validated in bovine milk in the range 2-150 µg kg(-1) for all antibiotics; for four compounds with maximum residue limits higher than 100 µg kg(-1) , the validation interval has been extended until 333 µg kg(-1) . The estimated performance characteristics were satisfactory complying with the requirements of Commission Decision 2002/657/EC. Good accuracies were obtained also taking advantage from the versatility of the hybrid mass analyser. Identification criteria were achieved verifying the mass accuracy and ion ratio of two ions, including the pseudomolecular one, where possible. Finally, the developed procedure was applied to 13 real cases of suspect milk samples (microbiological assay) confirming the presence of one or more antibiotics, although frequently, the maximum residue limits were not exceeded. The availability of rapid multiclass confirmatory methods can avoid wastes of suspect, but compliant, raw milk samples. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Via G. Salvemini, 1, 06126, Perugia, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Moretti
authors.affiliation: Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di Sotto 10, 06123, Perugia, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Cruciani
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Via G. Salvemini, 1, 06126, Perugia, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Romanelli
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Via G. Salvemini, 1, 06126, Perugia, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Rossi
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Via G. Salvemini, 1, 06126, Perugia, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Saluti
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Via G. Salvemini, 1, 06126, Perugia, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Galarini
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004350:Drug Residues / Q000032:analysis*; D057230:Limit of Detection; D016014:Linear Models; D008892:Milk / Q000737:chemistry*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents
keywords: antibiotics; liquid chromatography high-resolution mass spectrometry; method validation; milk