Establishion Of LC-MS/MS Determination Method Of Erythromycin Residue In Swine Edible Tissues

Erythromycin(Erythromycin A)is a clinically important macrolide antibiotic with 14-membered ring(molecular is C37H67NO13).Erythromycin mainly usedto treat corynebacterium diphtheria,amoeba gondii,neisseria gonorrhoeae,staphylococcus aureus,trachomatis and legionella which are caused by multiclass microorganism infection.Veterinary drug residues which are caused by drug used unreasonable is harmful to human food safety.The study is to develop a method for determination of erythromycin in swine edible tissues by LC-MS/MS in order to provide a basis for the determination of erythromycin residues in edible tissues of swine.The research contents included:1.A method has been developed for the determination of erythromycin in swine edible tissues LC-MS/MS.T:he chromatographic conditions are chromatographic column:CAPCELL PAK(4.6 mm×150 mm,5?m),injection volume:5?L,column temperature:20 degrees,flow rate:0.5mL·min-1,mobile phase:acetonitrile and 0.5%ammonia solution(V:V=92:8),elution method:isocratic elution.Ion source:electrospray ionization ion source(ESI),mass spectrometry:and the multiple reaction monitoring mode,positive ionization mode detection.The study improved the pretreatment of erythromycin in animal foods with complex matrices.Pretreatment methods for extraction,purification and other treatment of erythromycin in muscle,liver,kidney,lung and intestine of swine were studied.The extraction solvent and the extraction method were optimized.The study finally determined that acetonitrile was used as the ertractant,and the de-lipid was repeated in n-hexane,After centrifugation at low temperature,it was determined by LC-MS/MS.2.Methods of detecting erythromycin residues in edible tissues of swine by LC-MS/MS were investigated.The results shows thatlinear ranges of erythromycin was in the rage of 5 to 200ng-mL"1.The correlation coefficient of standard curve was 0.999.Detection limit(LOD)was 1.5 ng-mL-1 and quantitative limit(LOQ)was 5 ng·mL-1.The relative recoveries of erythromycin were from 75%?115%,and the intraday and interd.ay coefficients were less than 10%.Swine edible tissue samples have good stability after stangding at room temperature,4? and-20? for one week(RSD<10%).The retention time of erythromycin and roxithromycin are 5.89 time and 8.43 time,respectively,and they can be separated well without any interference.Conclusion:The method is up to the requirement the demand of veterinary drug residues analysis.The method is simple in operation,high in accuracy,good in stability and strong in specificit:y,and is expected to be certifi.ed as a standard detection method after being verified by the laboratory.