The Establishment Of High-throughput Screening Platform For Multiple Veterinary Residues And The Security Control Of Raw Milk

The production of raw milk is a dynamic and consecutive process,and the quality of raw milk may change every day.The data gained in-time can't predict the future trends.A high performance liquid chromatography tandem time-of-flight mass spectrometry method was established for the high-throughput determination of veterinary drug residues in raw milk.And it was used to screen veterinary drug residues in raw milk.The screening data was used to establish an early-warning method to predict the veterinary drug residues in raw milk.The main conclusions of this paper are as bellows:?1?A library of 174 veterinary drug residues was built,including beta-lactams,beta-agonists,avermectins,benzimidazole,macrolides,non-steroidal anti-inflammatory drugs,sulfonamides,anti-coccidiosis agent,quinolones,steroids,lincosamides,chloramphenicol,tetracycline,glucocorticoid,nitromidazoles,tranquilizers and others.And the information of the library consists of Chinese name,English name,molecular formula,CAS number,molecular mass,retention time.?2?An extracted method and a HPLC/Q-TOF-MS/MS method were established,then the LC-MS/MS method was validated of LOD,linearity,recovery and precision.The implementation steps were:the target compounds were extracted by acetonitrile and purified by freezing,and then analysed by LS-MS/MS.A Poroshell 120 EC-C18 column?3.0×150 mm,2.7?m?was used,and 0.1%formic acid-water/methanol system was chosen as mobile phase with a gradient elution program.In addition,the ESI was used with positive mode.The results show that the method has a good linearity?>0.9900?and a low LOD?<10 ng/g?for most of compounds,and 99 of them have good recoveries,from 70%to 130%with RSD from 1.03%to 9.65%at 50ng/g quality control concentration.Finally,the method was successfully applied into the screen-testing of veterinary drug residues in raw milk,with high efficiency and sensitivity.?3?The HPLC/Q-TOF-MS/MS method was applied to screen veterinary drug residues in raw milk in shanghai.The screening arrangement was:one batch a week,and 50 raw milk samples a batch,300 raw milk samples in all.The screening result was:in total,42 kinds of veterinary drug residues were tested out,including steroids?12?,glucocorticoids?6?,tranquilizers?5?,quinolones?5?,sulfonamides?3?,beta-agonists?3?,beta-lactams?2?,anti-coccidiosis agent?2?,nitromidazole?1?,benzimidazole?1?,lincosamide?1?and others?1?.?4?A Pn Shewhart control chart of prednisone was established according to the statistical results of screening veterinary drug residues in raw milk.The result showed that the result of6 batches was stable.And the Pn Shewhart control chart was suitable for the early-warning of future residues of prednisone in raw milk.Besides,the Pn Shewhart control chart was applied to control the 7^th batch.Two hypothetical results were investigated in this paper:?1?6 raw milk samples were tested out of prednisone,and the situation was analysed by the Pn Shewhart control chart,which showed that the result of 7 batch was normal.?2?10 raw milk samples were tested out of prednisone,and after analysed by the Pn Shewhart control chart,an abnormal situation happened?Pn=10>UCL=9.52?.So the early-warning was triggered.The HPLC/Q-TOF-MS/MS method established in this paper has good stability and can be applied into the fast screening of veterinary drug residues in raw milk.