Veterinary Drugs Residue Methods


Category Antibacterial substances, including sulfonamides and quinolones
Drug Class Name Florfenicol, a fluorinated synthetic analog of thiamphenicol
Method Title Confirmation of Florfenicol by GC/MS
Method Date 2006/08/07
Method Type Confirmatory, Quantitative
Scope and Application This method is used to confirm the presence of florfenicol (as florfenicol amine) in bovine liver and muscle.
Method Summary Florfenicol is extracted from an entire sample that is trimmed of extraneous connective tissue and sliced into small cubes before thorough homogenization/blending. Dichloromethane is used to extract neutral lipids. The homogenate is converted to florfenicol amine (FA) by acid catalyzed hydrolysis. A mixture of n-butaneboronic acid and N,N-dimethyl-formamide is used for derivatization. Following centrifugation, the aqueous layer is removed and alkalinized with NaOH to convert FA to its free base. FA is then extracted into ethyl acetate and transferred into borosilicate culture tube. The extracts are evaporated to dryness and the residue re-dissolved in the derivatizing reagent prior to analysis by GC/MS in selective ion monitoring mode. A fused silica capillary analyticalc column is used.
Applicable Concentration Range Florfenicol (florfenicol amine) may be quantified in bovine liver and muscle at ≥ 500 µg kg -1 and ≥ 300 µg kg -1 concentration levels, respectively.
QC Requirements See the attached SOP
Method Source USDA-FSIS
Method SOP PDF icon SOP