Study On Multi-Residue Analysis Of Veterinary Drugs In Chilled Meat

In this study,high-throughout approaches for determination of veterinary drug residues based on standard methods were developed,in order to solve the complex and time-consuming problems of available methods.Majority of veterinary drug residue specified in the sampling rules of food safety supervision department are included.Monitoring and studying on the veterinary drug residue levels in chilled fresh meat in Shandong Province were carried out.The main research results are as follows:1.A method for detection of clenbuterol hydrochloride,ractopamine and salbutamol in chilled fresh meat based on the GB methods was developed.including enzymatic hydrolysis,extraction by ammonium acetate,protein removing,secondary extraction with MTBE-ethyl acetate,and mixed cationic solid phase extraction(SPE-MCX),finally analyzed by UPLC-MS/MS.Compared with standard methods,it is time-consuming,easy-operating,and repeatable.Meanwhile,a high-throughout detection method for multi-residues of veterinary drugs in 39 chilled fresh meat was established.After extracted by acetonitrile,purified by hexane and HLB solid phase extraction,UPLC-MS/MS was employed to detect tetracyclines,sulfonamides,hormones,macrolides,quinolones,nitroimidazole and chloramphenicol residues in chilled fresh meat.It has the characteristics of high-throughout and easy to operate.2.Two proposed approaches were validated,in which the correlation coefficients were all greater than 0.994.Method limits of quantitation(MQLs)were in the range of 0.080-4.6?g/kg,while recoveries and relative standard deviations(RSD)at the three spiked concentrations were at the range of 79.5 %-114.0% and 1.6%-8.3% respectively.Comparing with standard methods,there were no significant difference in precision and accuracy,whereas higher sensitivity and lower detection limits were appeared in developed methods.3.238 batches of chilled fresh pork,beef and mutton purchased in Qingdao,Yantai,Jining and Tai'an were carried for test between 2018 and 2019.Twenty-six kinds of veterinary drug residues in 42 kinds were detected.In which tetracyclines and sulfonamides appeared mostfrequently,while the forbidden drugs such as norfloxacin,chloramphenicol and salbutamol were found occasionally.The levels of veterinary drug residues in chilled fresh beef and mutton are lower than that of in chilled fresh pork.Comparing with standard methods,established methods in this study have the features of lower detection limits,very close detecting results,which makes the developed methods appropriate for mass and high-sensitivity screening and determination of veterinary drug residues in chilled fresh meat.