Determination of tissue residue levels of emamectin benzoate in sea bass (dicentrarchus labrax, linnaeus, 1758) farmed in the mediterranean region

The aim of this study was to determine the residual levels of Emamectin Benzoate (EB), which is used as an antiparasitic drug in European sea bass fish, in the muscular skin tissue of the fish as a result of different dose applications and to determine the drug residue clearance times. The study was carried out on 369 European sea bass fish (Dicentrarchus labrax, Linnaeus 1758) with a live weight of approximately 100 grams at a water temperature of 19 ± 0,8 °C. The fish were divided into four groups, one control group and three experimental groups. In the experiment, the fish in the control group were given drug-free feed and the fish in the experimental groups were given feed containing 50, 100, 150 µg/kg EB orally for 7 days. Afterwards, 9 fish samples were randomly sampled from the control group on days 0, 7, 8, 9, 13, 17, 21 and 28 and from the experimental groups on days 7, 8, 9, 13, 17, 21, 28, 42, 56 and 70 of the drug administration. Residue levels in muscular skin tissue were determined by LC MS/MS. The highest residue levels were reached on day 8 in all study groups. Again, no value above the detection limits was detected in all study groups as of the 28th day. As a result of calculations using the European Medicines Agency (EMA) software (WT 1.4 by P. Heckman), withdrawal periods of 24,06 days for 50 µg/kg dose, 43,32 days for 100 µg/kg dose and 39,63 days for 150 µg/kg dose were determined. Although residue levels for all groups in our study were below the detection limits after the 28th day, it is recommended that similar studies should be carried out at different temperatures for European sea bass and EB-treated fish should be consumed by paying attention to the withdrawal periods determined against residue risk. Key Words: Dicentrarchus labrax, Linnaeus 1758, emamectin benzoate, residue