title: Determination of furaltadone and nifursol residues in poultry eggs by liquid chromatography-electrospray ionization tandem mass spectrometry.
abstract: The use of nitrofurans as veterinary drugs has been banned from intensive animal production in the European Union (EU) since 1993. The objective of the present study was to evaluate the accumulation and depletion of furaltadone and nifursol and their side-chain metabolites 5-methylmorpholino-3-amino-2-oxazolidinone (AMOZ) and 3,5-dinitrosalicylic acid hydrazide (DNSAH) in eggs after administration of therapeutic and subtherapeutic doses of the drugs to laying hens during three consecutive weeks. LC-MS/MS, with positive and negative electrospray ionization methods, was used for the determination of parent compounds and metabolites in yolk and egg white and was validated according to criteria established by Commission Decision 2002/657/EC. The decision limit (CCα) and the detection capability (CCβ) of the analytical methodology for metabolites were 0.1 and 0.5 μg/kg for AMOZ and 0.3 and 0.9 μg/kg for DNSAH, respectively. For the parent compounds, CCα and CCβ were 0.9 and 2.0 μg/kg for furaltadone and 1.3 and 3.1 μg/kg for nifursol, respectively. The data obtained show that the parent compounds are much less persistent than their side-chain metabolites in either yolk or egg white. Between the studied metabolites, AMOZ is the most persistent and could be detected in either yolk or egg white three weeks following withdrawal from treatment.
authors.affiliation: INRB-LNIV,  Laboratório Nacional de Investigação Veterinária , Estrada de Benfica 701, 1549-011 Lisboa, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Barbosa
authors.forename: Andreia
authors.initials: A
authors.lastname: Freitas
authors.forename: José Luis
authors.initials: JL
authors.lastname: Mourão
authors.forename: Maria Irene
authors.initials: MI
authors.lastname: Noronha da Silveira
authors.forename: Fernando
authors.initials: F
authors.lastname: Ramos
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000032:analysis*; D002645:Chickens; D002853:Chromatography, Liquid / Q000379:methods*; D004032:Diet / Q000662:veterinary; D004350:Drug Residues / Q000032:analysis; D004531:Eggs / Q000032:analysis*; D005260:Female; D005506:Food Contamination / Q000032:analysis; D009581:Nitrofurans / Q000008:administration & dosage / Q000032:analysis*; D023303:Oxazolidinones / Q000008:administration & dosage / Q000032:analysis*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D019155:Veterinary Drugs / Q000032:analysis
chemical_list: D000890:Anti-Infective Agents; D009581:Nitrofurans; D023303:Oxazolidinones; D019155:Veterinary Drugs; C007795:furaltadon; C032119:nifursol