RESUMO
A chemiluminescent enzyme immunoassay (CLEIA) was compared to an ultraperformance liquid chromatography tandem mass spectroscopy (UPLC-MS/MS) procedure for the analysis of zeranol and its metabolites in bovine tissue samples. Apparent recoveries from fortified samples by both methods were comparable at 0.5-4.0 µg/kg and a significant correlation was obtained. For CLEIA analysis, hapten mimicking the analyte was first synthesized and conjugated with the carrier protein bovine serum albumin as the immunogen to produce monoclonal antibody. The obtained antibody showed extensive cross-reactivity toward zeranol metabolites (zearalanone). The limit of detection of CLEIA and UPLC-MS/MS was 0.05 µg/kg and 0.5 µg/kg, respectively. Recoveries of both methods for fortified samples were higher than 75.0% with the coefficient of variation less than 15%. These results indicated that the combination of screening with CLEIA and confirmation with UPLC-MS/MS for zeranol and its metabolites would be a reliable method for a large number of bovine samples.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Técnicas Imunoenzimáticas/métodos , Fígado/química , Medições Luminescentes/métodos , Músculo Esquelético/química , Espectrometria de Massas em Tandem/métodos , Zeranol/análise , Animais , Bovinos , Hormônio do Crescimento/análise , Hormônio do Crescimento/metabolismo , Fígado/metabolismo , Músculo Esquelético/metabolismo , Zeranol/metabolismoRESUMO
A method based on ultra performance liquid chromatography-tandem mass spectrometry ( UPLC-MS/MS) has been proposed for the determination of coccidiostat residues in chicken skin and fat. The sample was extracted with the combination of methanol, acetonitrile, and acetic acid, and cleaned-up by Sep-Pak tC18 solid phase extraction cartridge. Data acquisition under positive electrospray mode was performed by applying multiple reaction monitoring for both identification and quantification. The limits of detection and quantification for halofuginone and robenidine were 7 μg/kg and 20 μg/kg, respectively. The limit of detection of salinomycin, monensin, narasin, maduramicin, and lasalocid was 5 μg/kg, and limit of quantification was 15 μg/kg. The recovery was 75% to 110% in the spiked concentration range from 15 μg/kg to 200 μg/kg, with intra-day precision lower than 12. 8%, and inter-day precision lower than 13 . 4%.
