title: Rapid method for the determination of metamizole residues in bovine muscle by LC-MS/MS.
abstract: Metamizole is a pyrazolone non-steroidal anti-inflammatory drug allowed for use in food-producing animals. According to Council Directive 96/23, residues of this drug have to be monitored because of the potential risk to consumers' health. Metamizole is hydrolysed to its marker residue 4-methylaminoantypyrine.This compound is further metabolised to three main metabolites: 4-formylaminoantipyrine, 4-aminoantipyrine and 4-acetylaminoantipyrine. The MRL of 4-methylaminoantipyrine in animal tissues is 100 µg kg(-1). Considering the above points, a method for the detection of four metamizole metabolites in bovine muscles was developed. Analytes were extracted from muscle by a mixture of acetonitrile and sodium acetate buffer. After centrifugation, the supernatant was passed through alumina cartridges, diluted with mobile phase and analysed by using LC-MS/MS. Four metamizole metabolites were separated on a C8 column in 23 min with a gradient of methanol:acetonitrile:ammonium formate solution and analysed by using positive ionisation. Validation of the method indicated a within-laboratory reproducibility in the range of 7-30% and recovery in the range of 45-95%. The method fulfils the criteria for confirmatory methods and, thanks to its labour efficiency, may also be used for screening purposes.
authors.affiliation: Department of Pharmacology and Toxicology, National Veterinary Research Institute, Puławy, Poland. jedzi@piwet.pulawy.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Jedziniak
authors.forename: Konrad
authors.initials: K
authors.lastname: Pietruk
authors.forename: Edyta
authors.initials: E
authors.lastname: Śledzińska
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Olejnik
authors.forename: Teresa
authors.initials: T
authors.lastname: Szprengier-Juszkiewicz
authors.forename: Jan
authors.initials: J
authors.lastname: Żmudzki
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis*; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D004177:Dipyrone / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis*; D009132:Muscles / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004177:Dipyrone