Establishment Of Detection Method For Bacitracin Residue In Animal Derived Food

Bacitracin is a peptide antibiotic produced by Bacillus,which has the functions of promoting animal growth,improving feed conversion rate,preventing and treating intestinal diseases of various animals,and is widely used in livestock and poultry breeding and feed production.The residue of bacitracin as an animal feed additive in animals can enter the human body through edible tissues of animals,thereby endangering human health.At present,the current national standards for detecting the residual amount of bacitracin in animal foods have great limitations,and are only applicable to the three tissues of muscle,liver and kidney of swine,and the operation of the method is complicated.Therefore,it is urgent to establish a rapid,sensitive and suitable for a variety of animal tissues including muscle,fat,liver,kidney tissue of swine,cattle and poultry,as well as high performance liquid chromatography-tandem detection of bacitracin residues in eggs,milk and milk powder.Mass spectrometry is a new national standard to ensure the safety of animal food and promote the development of foreign trade.According to the test method,the process is as simple as possible,and the animal tissue is as full as possible.This subject undertakes the revision task of "Determination of Bacitracin Residues in Animal Foods by High Performance Liquid Chromatography-Tandem Mass Spectrometry".It is easier to operate and has a wider range of detection methods to meet the detection needs of bacitracin residues in animal foods.Based on a large number of literatures at home and abroad,this experiment conducted a series of studies on the test methods and conditions,and finally established the HPLC/MS-MS method for the detection of bacitracin residues in animal foods.The method is based on the principle of being accurate,practical,fast,and in line with international standards,strictly follows the scientific basis,and finally completes the establishment of standard testing methods,and has carried out methodological verification at the Jiangsu Provincial Animal Product Quality Testing Center.The results show that the method has good specificity,linearity,accuracy and precision,and can quickly,accurately and sensitively detect the content of bacitracin in animal food.1 Determination of bacitracin residues in animal derived foods by high performance liquid chromatography-tandem mass spectrometry.The aim of this study was to establish a HPLC-MS/MS method for the determination of bacitracin residues in muscle,fat,liver,kidney tissue of swine,cattle and poultry and eggs,milk and milk powder.The sample was deproteinized by a 10%trichloroacetic acid acetonitrile solution,and the extract was repeatedly extracted twice with a 0.5%aqueous solution of trifluoroacetic acid,and the combined supernatant was centrifuged by nitrogen to obtain a reserve liquid.The reserve liquid is purified by Oasis HLB solid phase extraction column,eluted by Acquity UPLC ? BEH C18 column,and quantitatively analyzed by HPLC-MS/MS method.The detection limit of bacitracin was 50 μg·kg-1,and the limit of quantification was 100μg·kg-1.The peak position is basically free of other impurities and the specificity is good.The linear relationship was good in the range of 100μg·kg-1 to 5000 μg·kg-1,and R2 was more than 0.99.The recovery rate of bacitracin was 80.58%～109.41%under the four added concentration levels of limit of quantitation,low,medium and high.The relative standard deviation within the batch was between 0.45%and 9.97%,and the relative standard deviation between batches was between 2.79%and 11.13%.2 Review and verification of《Determination of bacitracin residues in animal derived foods by high performance liquid chromatograhy-tandem mass spectrometry》.After the development and completion of the standard test method,the methodological verification was further carried out at the Jiangsu Provincial Animal Product Quality Inspection and Testing Center to ensure the accuracy and reliability of the test method.The verification test repeats the test method of Chapter 2.The verification results show that the method has good specificity.The detection limit was 50 μg·kg-1 and the limit of quantification was 100 μg·kg-1.The linear relationship was good in the range of 100 μg·kg-1 to 5000μg·kg-1,and R2 was more than 0.99.Under the four concentration levels of limit of quantitation,low,medium and high,the recovery rate of bacitracin was 81.23%～108.84%,the relative standard deviation within the batch was between 0.25%～10.27%,and the relative standard deviation between batches was between 1.31%～10.58%.The test results show that the method for determination of bacitracin residues in animal foods by high performance liquid chromatography-tandem mass spectrometry is accurate and reliable,and has good repeatability.