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INTRODUCTIONNitrofurans are broad spectrum antibacterial agents known as Schiff's bases, which are derivates of nitrofuraldehyde. In veterinary medicine, it were used in the treatment of gastrointestinal and dermatological infections in beef, pork, poultry, fish and shrimp, and also applied as a contribution to the systemic and feed as growth promoters. In addition, nitrofurans were used in the treatment of bacterial infections in bee colony health (1).Nitrofurans have been prohibited from use in food-producing animals in the European Union In this study we have devoloped and validated a confirmatory analysis method for nitrofuran metabolites, which is in accordance with European Commission Decision 2002/657/EC requirements. Nitrofuran metabolites in honey, milk, poultry meat and fish samples were acidic hydrolised followed by derivatisation with nitrobenzaldehyde and liquid-liquid extracted with ethylacetate. The quantitative and confirmative determination of nitrofuran metbolites was performed by liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) in the positive ion mode. In-house method validation was performed and reported data of validation (specificity, linearity, recovery, CC α and CC β ). The advantage of this method is that it avoids the use of clean-up by Solid-Phase Extraction (SPE). Furthermore, low levels of nitrofuran metabolites are detectable and quantitatively confirmed at a rapid rate in all samples. and most countries due to public health and safety concerns, particularly in relation to the carcinogenic potential of either the parent compounds or their metabolites (2). The use of nitrofurans in foodproducing animal was prohibited in Turkey (3). A minimum required performance limit (MRPL) for nitrofurans is set in European Union for the metabolites in poultry meat and aquaculture products at the level of 1 μg kg -1 for all metabolites (4). DEVELOPMENT AND VALIDATION OF CONFIRMATORY METHOD FOR ANALYSIS OF NITROFURAN METABOLITES IN MILK, HONEY, POULTRY MEAT AND FISH BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRYAnalytically, residues are checked only for marker metabolites of the 4 nitrofuran chemicals, in particular: 3-amino-2-oxazolidinone (AOZ) for furazolidone, 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ) for furaltadone, 1-aminohydantoin (AHD) for nitrofurantoin and semicarbazide (SEM) for nitrofurazone (5).Several methods have been reported in the analysis of nitrofuran metabolite in food samples. These include thin-layer chromatography (TLC) (6), high performance liquid chromatography diode-array detector (HPLC DAD) (7) and UV detector (8, 9), liquid chromatography-mass (10,11,12). LC-MS/MS analyses were considered very sensitive and commonly used the confirmatory analysis. Original Scientific ArticleIn the current study, a method was devoloped and validated for quick confirmatory analysis of nitrofuran metabolites (AOZ, AMOZ, AHD and SEM). All samples were acidic hydrolised followed by derivatisation with nitrobenzaldehyde and liquid-liquid ex...

Two commercially available long-acting oxytetracycline hydrochloride formulations (Primamycin LA (Pfizer) and Terralent 20% LA (I.E. Ulagay)) were administered by the intramuscular route to 20 clinically healthy sheep at a dose of 20 mg/kg. The study was performed in a two-period crossover design. Plasma samples were analysed by high-pressure liquid chromatography. The mean maximum concentrations (C (max)) was 8.00 +/- 2.05 microg/ml and 8.61 +/- 1.42 micro/ml, respectively. The mean area under the concentration time curve (AUC) values were 154.95 +/- 50.37(microg h)/ml and 161.70 +/- 47.02(microg h)/ml, respectively. The 90%confidence intervals for the ratio of C (max) and AUC values for the test and reference product are with in the interval 70-143% for C (max) and interval 80--125% for AUC proposed by EMEA. It was concluded that Primamycin LA and Terralent 20% LA formulations are bioequivalent in their rate and extent of drug absorbtion.

Our study developed a quick method for confirmatory analysis of avermectins (abamectin B, doramectin, ivermectin B, eprinomectin B, and moxidectin) in bovine milk according to the European Commission Decision 2002/657/EC requirements. Avermectins were liquid-liquid extracted with acetonitrile, followed by an evaporation step, and then analyzed by liquid chromatography/electrospray ionization tandem mass spectrometry in the negative ion mode. An in-house method validation was performed and the data reported on specificity, linearity, recovery, limit of detection, limit of quantitation, decision limit, and detection capability. The advantage of this method is that low levels of avermectins are detectable and quantitatively confirmed at a rapid rate in milk.

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