Study On Detection Technology Of Peptide Antibiotic Residues In Infant Foods

Polypeptide antibiotics are widely used as veterinary drugs that added to animal feeds for their use in the prevention and treatment of animal infectious diseases,promote feed conversion and increase the growth rate of animals because of their potent resistance to Grams,fungi and viruses.But excessive addition or abuse can lead to animal or product residues in the body of such drugs,resulting in severe food safety problems.As the peptide antibiotics have severe toxicity and side effects,humans through the consumption of animal residues containing such drugs or products will cause health risks and damage.The group of infant and child as a part of human,which has the lower relatively in the immune resistance,so infant food quality and safety is particularly important.In this paper,we established the method for the detection of peptide antibiotic residues in infants and young children,which can be monitored and controlled at the trace level,so as to provide data support for the detection of drug residues in infants and young children.The main research contents include the following parts:1.The first chapter summarizes the development of peptide antibiotics,the harm and control of peptide antibiotic residues and the detection technology and methods of peptide antibiotics both at home and abroad.2.In the second chapter,solid phase extraction-high performance liquid chromatography-tandem triple quadrupole mass spectrometry was developed for simultaneous determination of gramicidin S,bacitracin,polymyxin B and polymyxin E in infant formula milk powder.The samples were extracted with 0.1% formic acid-methanol,the protein was removed with acetonitrile and degreased with n-hexane,purification by Oasis HLB solid phase extraction column.Multiple reaction monitoring(MRM)mode was used in the determination,external standard method for quantitation.The results show that the good linearity of the four targets in the linear range of 20~2000 ?g·kg-1.The LOD is 5~10 ?g·L-1.The LOQ is 20~50 ?g·kg-1.The average recoveries were in the range of 82.8%~101.2%.Intr-aday precision and inter-day precision was in the range of 2.2%~8.8% and 2.7%~9.8%,respectively.3.In the third chapter,QuEChERS-HPLC-MS/MS was developed for simultaneous determination of gramicidin S,bacitracin,and polymyxin E in milk.Acidificated acetonitrile as extraction solvent and removal of protein in milk samples,purification of samples by N-propyl ethylenediamine(PSA)and C18.Electrospray ionization(ESI+)mode,multiple reaction monitoring(MRM)mode and external standard method for quantitation was used in the determination.The results showed that the linearity coefficient was more than 0.995 in the range of 10~1000 ?g·kg-1,and the LOD was 3~10 ?g·kg-1 and the LOQ was 10~30 ?g·kg-1.The recoveries were 81.2~93.6% at different concentrations and the RSD were 3.1~8.9%.