EXTRACCIÓN DE OXITETRACICLINA EN CARNE DE POLLO: ESTUDIOS DE RENDIMIENTO CON AUMENTO DE LA FASE POLAR DEL SOLVENTE DE EXTRACCIÓN Oxytetracycline Extraction in Chicken Meat: Studies on Yield increasing Polar Phase in Extraction Solvent

Consumption of food that contains oxytetracycline (OTC) residues may produce several toxic effects in human beings. In order to extract and quantify such residues in biological matrices, like chicken meat, several methods have been developed. Among these methods, liquid-liquid extraction is the mostly used, because is quick, simple and inexpensive. This extraction method was applied by Furusawa for OTC in chicken, using acetonitrile/hexanes in a 5:4 proportion, obtaining an 88% recovery. The objective of this research was to study extraction of OTC in chicken meat assayed by Furusawa, raising polar solvent proportion in relation to hexanes (2:1), and further quantifying by means of high performance liquid chromatography (HPLC). Twenty four portions of 1 g from 3 OTC free chickens were fortified with OTC standard solutions: 0.1, 0.2, 0.5 and 1 μg/g, obtaining 6 fortified samples for each concentration, stored for 12 hours at 4°C. Antibiotic extraction was performed using acetonitrile/hexanes in 5:4 and 2:1 proportions. Recovery, precision and sensitivity were analyzed in all samples. Either 5:4 or 2:1 proportions, 0.2 μg/g concentration obtained the higher recovery, 91.5 and 92.5%, respectively; however when OTC concentrations raised, recovery became lower. Precision increased at 0.5 μg/g concentration, but, fell down when concentration duplicated: 1 μg/mL. Detection limit obtained for OTC extraction using acetonitrile/hexanes in 2:1 proportion were 0.09 μg/g. Deproteinization is recommended previously to extraction process.