Studies On The Pretreatment And Determination Method Of HPCE In Residues Analysis Of Penicillin Antibiotics

Penicillins areβ-lactam antibiotics widely used in veterinary medicine for the treatment and prevention of disease.Using them can result in the presence of residues in edible tissues which can lead to health problems for individuals who are hypersensitive to penicillins.Bioassays are the most commonly employed methods for determining penicillin residues in food,it's non-specific and not quantitative.Sensitive,specific chemical assays are required forβ-lactam antibiotics residues.Our country has not any developed method for the determination of multi-residue of penicillins in animal derived food.In order to control the food safety and protect the benefits of our country,we developed a method to determine the residues in animal derived food based on the experience of our laboratory and literatures.Most chemical penicillin methods are single residue methods.Multi-residue methods have been developed for the determination of three penicillins but very few ones are available for the simultaneous determination of both. This study described here focuses on the simultaneous determination of penicillin, ampicillin and amoxicillin in chicken muscle tissue.1.This study reports four pretreatment methods to extract penicillins in chicken muscle tissue sample including Solvent Extraction,Solid Phase Extraction,Matrix Solid Phase Dispersion,MSPD/SPE.By comparison,a simple sample extraction procedure—SPE clean-up can be chosen to treat sample finally.It is a method of high precision,high recovery,easy operation and good practicability.The following is the concrete operation. The residue is extracted with phosphate buffer;protein is removed with acetonitrile rather than clean up by C₁₈ SPE cartridge which has been conditioned previously with methanol and water.Using n-hexane to wash the cartridge,after which the penicillins were eluted by using 80%acetonitrile.The acetonitrile is dried by nitrogen at 40℃.2.A high performance capillary electrophoresis method for the simultaneous determination of residues of three Penicillins antibiotics in chicken muscle tissue is described as well.Conditions are as follows:30mmol/L sodium tetraborate buffer(using 6mol/L hydrochloric acid adjusted to pH7.8),detection wavelength 198 nm,running voltage 18 kV,and operated temperature 25℃.Three antibiotics are separated completely. The liner range is 0.5～100μg/mL,and the coefficients are 0.9989 to 0.9998.3.SPE—HPCE method for the simultaneous determination of residues of three Penicillins antibiotics in chicken muscle tissue is described.The residues of penicillins in chicken muscle are extracted with phosphate buffers,protein removed with acetonitrile, degreased with n-hexane and cleaned up with SPE.The results show that,with the method of capillary electrophoresis before clean up with SPE,the detection limit of penicillin, ampicillin and amoxicillin is 0.25,0.3,0.1μg/g;the RSD of precision is less than 12%;the average recovery rate of the preparation is in the range of 77.7%～95.1%.According to the references the residual analyses for penicillins in chicken muscle tissues with HPCE method were few at home and abroad.HPCE is a common method to detecting penicillins residues.This study reports four pretreatment methods to extract penicillins in the sample of chicken muscle tissues sample,and select a best one through comparisons.The information in this study may be useful to related experiments.