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...

This study provides insight into the development and validation of the simple, rapid and sensitive method of Liquid Chromatography-Tandem Mass Spectrometry for determining the residues of dexamethasone in bovine milk. The maximum residue limit for dexamethasone in bovine milk is 0.3 ng/ml−1. Chromatographic separation was achieved on an Agilent Proshell 120 SB:C18 (2.7µm 100x3.0 mm) column. The bovine milk was extracted with ethyl acetate, and the evaporated elution was dissolved with hexane, water and methanol, and analyzed by the LC-MS/MS method. The mobile phase A was a solution of 5 Mm ammonium formate in water, while the mobile phase B was 0.1% formic acid in acetonitrile. The calibration graphics were prepared within the range of 0.15–0.6 ng/ml−1, and a successful linearity was achieved (r ≥0.999). The limit of detection was 0.016 ng/ml−1. The decision limit (CCα) and detection capability (CCβ) were 0.34 and 0.38 ng/ml−1, respectively.