solid-phase extraction and simultaneous determination of tetracycline residues in edible cattle tissues using an hplc-fl method

in this assay, edible cattle tissues from local markets of ardabil, a province of iran, were examined for residues of tetracycline antibiotics (tetracycline, oxytetracycline and chlortetracycline). in total, 110 samples of triceps, gluteal muscle, diaphragm, kidney and liver were randomly obtained from the local markets of the city of ardabil. solid-phase extraction (spe) and high-performance liquid chromatography (hplc) methods were used to extract and analyze tetracycline antibiotic (tc) residues, respectively. the mean amount of total tc residues in all tested samples was 226.3 ± 112.5 ng/g and the mean amount of the total tc residues in triceps, gluteal muscle, diaphragm, kidney and liver samples were 176.3 ± 46.8, 405.3 ± 219.6, 96.8 ± 26.9, 672.4 ± 192.0 and 651.3 ± 210.1 ng/g, respectively. additionally, 25.8% of muscle samples, 31.8% of liver samples and 22.7% of kidney samples contained amounts of tc residues beyond the maximum residue limit (mrls). to reduce the tc residues found in edible cattle tissues, regulatory authorities should ensure that the cattle would undergo the proper withdrawal period from tcs before the slaughtering.