Veterinary Drugs Residue Methods


Category Antibacterial substances, including sulfonamides and quinolones
Drug Class Name Sulfonamides
Method Title Quantitation and Confirmation of Sulfonamides by Liquid Chromatography Tandem Mass Spectrometry (LC-MS-MS)
Method Date 2011/05/11
Method Type Confirmatory, Quantitative
Scope and Application This method can be used to quantify and confirm the presence of the following sulfonamides in tissue (muscle and liver tissues of porcine, bovine, and avian species), processed products and catfish: sulfapyridine, sulfathiazole, v Sulfadiazine, sulfachloropyridazine, sulfamethazine, sulfamethoxazole, sulfamethoxypyridazine, sulfaquinoxaline, sulfaethoxypyridazine, sulfadimethoxine, sulfadoxine, sulfamerazine, sulfisoxazole, sulfamethizole.
Method Summary Homogenized liver and muscle samples are extracted in ethyl acetate (and 3.2M HCl) by centrifugation after which the ethyl acetate layer is discarded. Hexane is then added and the mixture centrifuged again to remove fat. Sodium acetate and ethyl acetate are added and the mixture re-centrifuged. The mixture is then evaporated to dryness and the residue dissolved in methanol plus mobile phase. This mixture is then centrifuged one final time and filtered prior to analysis by LC-MS/MS in positive ESI mode. A Zorbax Eclipse XDB-C18 analytical column is used to separate the sulphonamides.
Applicable Concentration Range The sulfonamides sulfapyridine, sulfathiazole, sulfadiazine, sulfachloropyridazine, sulfamethazine, sulfamethoxazole, sulfamethoxypyridazine, sulfaethoxypyridazine, sulfadimethoxine, sulfadoxine, sulfamerazine, sulfisoxazole and sulfamethizole may be quantified at ≥50 µg kg-1 concentration level, while sulfaquinoxaline may be quantified at ≥ 100 µg kg-1.
QC Requirements See attached SOP
Method Source USDA-FSIS
Method SOP PDF icon SOP