| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1215522 | Journal of Chromatography B | 2014 | 6 Pages |
•This is the first report that established an analytical method for the determination of toltrazuril and its metabolites in skin + fat of chicken and pig.•A reliable UPLC-UV method for simultaneously detecting toltrazuril and its metabolites in skin and fat of chicken and pig was developed.•The developed method has been successfully applied to the depletion study of toltrazuril drug residues in chicken skin + fat after experimental application of toltrazuril to chicken. The recommended withdrawal period with oral administration based on our research is 24.18 days.
A reliable method for the simultaneous determination of toltrazuril and its main metabolites (toltrazuril sulphone and toltrazuril sulphoxide) in chicken and pig skin + fat was developed and validated. Analytes were extracted from skin + fat with acetonitrile. The crude extracts were subjected to liquid–liquid extraction with n-hexane, and then further cleaned using primary secondary amine and Oasis™ MAX solid phase extraction cartridges. Chromatographic separation by UPLC-UV was performed on a C18+ reversed-phase column with gradient elution. Relative recovery from the spiked samples ranged from 84.8% to 109.1%. Limits of detection and quantification for the analytes were within 25–37.5 μg kg−1 and 50–75 μg kg−1, respectively. The developed method has been successfully applied to the depletion study of toltrazuril drug residues in chicken skin + fat. The recommended withdrawal period with oral administration based on our research is 24.18 days.
