Veterinary Drugs Residue Methods


Category Anticoccidials, including nitroimidazoles
Drug Class Name Nitorimidazoles
Method Title Confirmation of Nitroimidazoles by ESI-LC/MS/MS
Method Date 2005/02/07
Method Type Confirmatory, Quantitative
Scope and Application This method is suitable for the analysis/confirmation of hydroxy-dimetridazole and hydroxy-ipronidazole in swine and poultry muscle.
Method Summary Homogenized meat samples mixed with K2HPO4, NaCl and ethyl acetate are extracted by centrifugation after thorough shaking. The ethyl acetate is then evaporated. More ethyl acetate is added along with HCl and the extract mixed with hexane. After gentle swirling, the bottom aqueous layer is collected into a scintillation vial or small beaker while avoiding any emulsion. The extract pH is then adjusted to 4.8-5.2 followed by sample clean-up using a C18 SPE column. The final methanol eluate is evaporated to dryness and the residue dissolved in water before filtration through 0.22 micrometer syringe filter for analysis by LC-MS/MS in ESI MRM mode. A Phenomenex RP-C-18 analytical column is used
Applicable Concentration Range Hydroxy-dimetridazole and hydroxy-ipronidazole levels of ≥ 0.20 µg may be reliably confirmed using this method.
QC Requirements See attached SOP
Method Source USDA-FSIS
Method SOP PDF icon SOP