Quantitative and qualitative determination of enrofloxacin residues in fish tissues

Abstract

Presence of enrofloxacin residues in fish liver, kidney and muscle tissue was investigated after per os application of the drug. For the purpose of determination of enrofloxacin, the following analytical methods were used: microbiological method - plate pH 8 with Escherichia coli ATCC 11303 and HPLC method with fluorescence detection. After a 5-day oral treatment of carps, enrofloxacin residues in tissues were determined up to the 10th day after the end of the drug application. Enrofloxacin content determined by the HPLC method was lower than MRL; drug residues were determined in liver on the 6th day after treatment, in kidney on the 7th day and in muscle on the 9th day after treatment. The results of enrofloxacin residues determination by screening method on the medium with E. Coli ATCC 11303, pH 8 show that this procedure can be used for qualitative determination of enrofloxacin. The screening method allows determination of enrofloxacin in fish tissues below the MRL. Cyprofloxacin was not detected in fish liver, kidney and muscle tissue.

Prisustvo rezidua enrofloksacina u jetri, bubregu i mesu riba ispitano je posle njegovog peroralnog aplikovanja. Za ispitivanje rezidua su korišćene: mikrobiološ ka metoda - ploča pH 8 sa Escherichia coli ATTC 11303 i HPLC metoda sa flurescentnom detekcijom. Posle petodnevne oralne terapije šarana rezidue enrofloksacina u tkivima riba su dokazane i devetog dana po prestanku terapije. Sadržaj enrofloksacina dokazan HPLC postupkom, niži od MRL vrednosti, u jetri je dokazan šestog dana po prestanku terapije, u bubregu sedmog dana a u mišićnom tkivu devetog dana po prestanku terapije. Rezultati utvrđivanja rezidua enrofloksacina skrining postupkom na podlozi pH 8 E.coli ATCC 11303 pokazuju da se ovaj postupak može koristiti za kvantitativno dokazivanje enrofloksacina. Skrining postupkom u tkivima riba mogu da se dokažu količine enrofloksacina ispod MRL vrednosti. Ciprofloksacin nije utvrđen u jetri, bubrezima i mesu riba.