A simultaneous determination method by HPLC for egg-residues sulfamerazine, sulfamethazine, sulfadimethoxine, furazolidone and zoalene was assessed. The drugs were extracted by dechloromethane. The extract after solvent evaporation, is partitioning in hexane/water and back-partitioning in dechloromethane and analysis by HPLC.
The average recovery rates of the above microbials from the egg spiked standard solution were approximately 81.2%, 87.6%, 92.5%, 86.1% and 79.3% respectively. The limit of detection of sulfamerazine, sulfamethazine and sulfamethoxine were in the levels of 0.2ppb, furazolidone and zoalene 0.5ppb respectively. According to this method 84 commercial eggs were examined. Sulfamethanzine was detected at levels of 0.005-0.008ppm in 3 eggs. Sulfadimethoxine was detected at levels of 0.012-0.019ppm in 4 eggs. No sulfamerazine, furazolidone and zoalene was detected in every samples. The residues of antimicrobial agent were safty level as food generally.
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