Determination Of Antibiotic Residues In Animal-Derived Food By High Performance Liquid Chromatography Tandem Mass Spectrometry

Penicillin and fluoroquinolone drugs are widely used in disease prevention and treatment of animals. However, using these antibiotics irrationally will lead to the remedy residue, which will damage to animals and human beings. Antibiotics are not toxic but they are easy to cause dangerous situations because many sensitive people will be allergic as swollen and itchy. Antibiotics can also affect the growth of the helpful microorganisms in human body. And if human use lower concentration of antibiotics for a long time then these antibiotics will lead to the dysbacteriosis and drug-resistance of bacteria, lowers immunity and pollute the environment.The purpose of this paper is to establish a determination of antibiotic residues in animal-derived food by high performance liquid chromatography tandem mass spectrometry.Chapter one:An overview of penicillins and fluoroquinolones was introduced. The significance of detecting antibiotics in animal-derived food and its detection methods.Chapter two:The method was established for the determination of eight penicillin antibiotics in milk sample by liquid chromatography tandem mass spectrometry. The separation was performed on an C18 column utilizing a gradient elution program of acetonitrile and water (containing 0.1% formic acid and 5mmol ammonium acetate) as the mobile phase. The milk samples were processed with ammoniation acetonitrile to denature the protein, and extract by ultrasonic and then defatted with n-hexane. The linear ranges were from 2 μg/kg to 200 μg/kg with the correlation coefficients were 0.9965 μg/kg to 0.9995 for all the 8 penicillins. The average recoveries of eight penicillins were 87.8% to 108.6% at two spiked levels:10,20 μg/kg with the RSD were 7.2% to 10.8%. The detection limits were of 0.05 μg/kg to 2.7 μg/kg and the quantification limits were of 0.17 μg/kg to 8.9 ug/kg.Chapter three:The method was established for the determination of eight fluoroquinolone antibiotics in milk sample by liquid chromatography tandem mass spectrometry. The separation was performed on an Cis column utilizing a gradient elution program of acetonitrile-methanol(50/50, v/v) and water (containing 0.2% formic acid) as the mobile phase. The sample was extracted with phosphoric acid and acetonitrile.After separate with high speed frozen centrifugation and concentrated with a rotary evaporator, the residue was dissolved with the mobile phase and then defatted with n-hexane. It was then analyzed with HPLC-MS/MS. The linear ranges were from 2 to 50 μg/kg with the correlation coefficients above 0.9956 μg/kg for all the eight fluoroquinolones. The average recoveries of eight fluoroquinolones were 65.4% to 119.6% at three spiked level:5,10,20 μg/kg with the RSD lower than 7.52%. The detection limits were of 0.0005 μg/kg to 0.22 μg/kg and the quantification limits were of 0.019 μg/kg to 0.74 μg/kg.Chapter four:The method was established for the determination of fourteen fluoroquinolone antibiotics in egg sample by liquid chromatography tandem mass spectrometry. The separation was performed on an Cis column utilizing a gradient elution program of acetonitrile-methanol(50/50, v/v) and water (containing 0.1% formic acid and 5mmol ammonium acetate) as the mobile phase. The milk samples were processed with phosphoric acid and acetonitrile denature the protein, and then concentrated with a rotary evaporator, and defatted with n-hexane two times. It was then analyzed with LC-MS. The linear ranges were from 2 μg/kg to 50 μg/kg with the correlation coefficients above 0.9808 μg/kg for all the fourteen fluoroquinolones. The average recoveries of fourteen fluoroquinolones were 68.3%～116.2% at two spiked level:10,20 μg/kg with the RSD were 0.32% to 5.46% The detection limits were of 0.056 4 μg/kg to 0.865 3 μg/kg and the quantification limits of 0.026 4 μg/kg to 0.4315 μg/kg.