Determination of Florfenicol Residues in the Muscle and Liver of Cultured Rainbow Trout in Iran by ELISA

Florfenicol is a broad-spectrum antibiotic, widely used in veterinary medicine. The aim of this study was to determine florfenicol residues in the muscle and liver of cultured rainbow trout in Iran by ELISA. The samples were collected from three areas (Kiar, Ardal, and Koohrang), considered as areas with high production of trout in the western part of Iran. Sampling was completed during the spring and summer of 2011. All of the samples were categorized into three weight groups (below 50g, 50 to150g and over 150g) and five individuals were randomly selected from fish belonged to each weigh group, and then collected samples sent for determination of antibiotic residues. The highest and the lowest antibiotic residues were 31.42±53.52 ng g-1 (>150 g fish) and 10.35±2.33 ng g-1 (<50 g fish) for liver samples and 48.84±50.36 ng g-1 (50-150 g fish) and 18.20±15.41 ng g-1 (> 150 g fish) for muscle samples, respectively. In different areas, the highest antibiotic levels were found in Koohrang and Ardal with mean of 37.00±63.61 and 15.33±10.45 ng g-1 for liver samples and 40.74±40.80 and 28.24±45.91ng g-1 for muscle samples. The results indicated that florfenicol residues are lower than the maximum permissible level has been announced by the European Union.