Abstract: The distribution of veterinary drug residues in pork meat during slaughter and pre-cooling was evaluated in this experiment. A total of 240 samples of pork and viscera were randomly collected according to sampling method specified in the Sampling operating specification for the livestock and poultry and their products in slaughtering enterprises (NY/T 1897-2010), and they were analyzed for 43 veterinary drug residues by enhanced matrix removal lipid (EMR-L) cleanup followed by ultra-high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS). Meanwhile, risk assessment of veterinary drug residues was carried out based on food safety index (IFS). The results showed that sulfamethazine, difloxacin and enrofloxacin were detected in the 240 samples. The detection rate of the 43 veterinary drugs was 5% at levels ranging from 2.43 to 19.94 μg/kg. The difference between the detection results after rigor mortis and maturation was not significant, indicating that there was no secondary pollution of the 43 veterinary drugs during slaughter and processing. At the same time, pork samples sold in Nanjing were collected and veterinary drug residues were detected in these samples with a detection rate of 4.4%. The IFS and values were found to be much less than 1, indicating that the levels of 43 veterinary drugs residues in pork products in Nanjing were acceptable.

Key words: enhanced matrix removal lipid; slaughter and processing; pork; veterinary drugs; risk assessment