Optimization Of Detection Methods For Three Kinds Of Veterinary Drug Residues In Animal Meat

Veterinary drug residues refer to the parent compounds and / or metabolites of veterinary drugs contained in any edible part of animal products,as well as the impurities related to veterinary drugs,including antibiotics,intestinal repellents,growth promoters,antigenic drugs,trypanosomes,tranquilizers,?-adrenergic receptor blockers,etc.Because of the great harm of veterinary drug residues,the supervision of veterinary drug residues in China is increasing day by day.In this experiment,three monitoring schemes of veterinary drug residues were established,and the detection methods of 14 veterinary drug residues by LC-MS/MS.The experimental results are as follows :1.Monitoring method of sulfonamide veterinary drug residues: the external standard method was used for quantitative analysis.After the optimization of pretreatment conditions such as extraction and purification,liquid chromatography conditions and mass spectrometry conditions,the best detection method was finally determined and an effective monitoring scheme was obtained.Using neutral alumina and C18 powder(1+1)with three times mass ratio as dispersant,acetonitrile aqueous solution(95+5)with 0.3% formic acid concentration as extractant,the ratio of sample to extractant was 1:10,and ultrasonic assisted extraction was used.Finally,the optimized on-line method was selected for testing.The standard curve of sulfonamide veterinary drug residues is in good shape in the range of 0-200 ?g/L,the correlation coefficient is above 0.99,the recoveries of the three levels are between 75%-115%,the relative deviation is less than 10%,and the quantitative limit is between 0.15-0.45 ?g/kg.2.Determination of tetracycline residues in veterinary drugs: the external standard method was used for quantitative analysis.After optimization of pretreatment conditions such as extraction and purification,liquid chromatography and mass spectrometry conditions,the best detection method was finally determined and an effective monitoring scheme was obtained.NA2EDTA-Mcllvaine buffer with p H value of 4.0-5.0 was selected as the extracting agent,the best ratio of material to liquid was 1:9,Oasis HLB solid phase extraction column was used as the purification column,and methanol ethyl acetate(10+90)was used as eluent.The standard curve of tetracycline veterinary drug residues is in good shape in the range of 0-500 ?g/L,the correlation coefficient is above 0.999,the recoveries of the three levels are between 80%-105%,the relative deviation is less than 10%,and the quantitative limit is between 0.25-0.50 ?g/kg.3.Determination of chloramphenicol residues: chloramphenicol is quantified by internal standard method,and thiamphenicol and florfenicol are quantified by external standard method.After optimization of pretreatment conditions such as extraction and purification,liquid chromatography and mass spectrometry conditions,the best detection method is finally determined and an effective monitoring scheme is obtained.Acetonitrile was selected as the extractant,the best ratio of material to liquid was 1:10,oasis HLB solid-phase extraction column was used as the purification column,ethyl acetate as the eluent,and the initial mobile phase was used for solubilization.Finally,the optimized on-line method was selected for detection.The standard curve of chloramphenicol veterinary drug residues is in good shape in the range of 0-200 ?g/L,the correlation coefficient was above 0.999,the recoveries of the three levels were between 75%-110%,the relative deviation was less than 10%,and the quantitative limit is between 0.02-0.10 ?g/kg.