Multi residue determination of 96 veterinary drug residues in domestic livestock and fishery products in South Korea

This study was to develop a multi-residue quantification method for determination of 96 veterinary drugs in livestock products (beef, pork, chicken, milk, egg) and fishery products (flatfish, eel, and shrimp) using liquid chromatography-tandem mass spectrometry. In addition, the purpose of this study was to verify the identification of veterinary drug residues by applying this analytical method to livestock and aquaculture animals. The coefficient of determination (r2) was more than 0.98 at the matrix-matched calibration curve. The proposed method was validated according to the CODEX guidelines (CAC/GL-71-2009), and most target compounds were found to be in acceptable quantities under the requirements of the validation guidelines. The limit of detection and limit of quantification ranged from 0.3 to 19.7 μg kg−1 and 1 to 65 μg kg−1. Samples (n = 581) were collected and analyzed to investigate the residues in target animal derived foods and 131 samples were detected (22.5%). In addition, only one rockfish sample exceeded the Korean MRL for sulfadiazine (523 μg kg−1; MRL: 100 μg kg−1) and trimethoprim (195 μg kg−1; MRL: 50 μg kg−1). The most frequently detected veterinary drugs were flumequine followed by oxytetracycline, enrofloxacin, trimethoprim, ciprofloxacin, and mebendazole. These results showed that we developed an acceptable analytical method of 96 veterinary drugs in animal derived foods and it will be useful for the safety management of veterinary drugs in livestock products, fish, and shrimp.