Study On The Residue Elimination Of Tilmicosin In Broiler

Tilmiconsin is a macrolide antibiotic formed a chemical modification of tylosin,and was first developed by Elancon Company in the 1980 s.Tilmicosin has a spectrum of antimicrobial activity,which can inhibit all of Gram-positive organisms and parts of Gram-negative bacteria and Mycoplasma.It is efficacious for the treatment of respiratory disease that caused by bacteria.besides,in Europe,tilmicosin is labeled for use in chickens.Reports on residue depletion of tilmicosin in food-producing animals were relatively less.In this study,high-performance liquid chromatography(HPLC)method was developed to determine the concentration of tilmicosin in broiler tissues.The residue elimination of tilmicosin was studied in edibility tissues of broiler.The results were to provide experimental basis for developing withdrawal time of tilmicosin in broiler by administered tilmicosin in drinking water(0.75g/L).The condition of HPLC-MS/MS was optimized using C18 analytical chromatographic column with acetonitrile and acetonitrile,tetrahydrofuran,dibutylamine phosphate buffer,water(110:55:25:810)as mobile phase in the isocratic elution.The calibration curves of tilmicosin were linear in the concentration range of 0.025?g/mL~10?g/mL,with correlation coefficients were more than 0.9998.The limit of detection(LOD)and quantification(LOQ)of the method for tilmicosin were 0.01?g/g and 0.025?g/g,respectively and the recoveries were in the range of 75.54%~94.82% with RSD of 0.76%~11.07% at0.025?0.5?5?g/g while blank samples were spiked with tilmicosin.This analytical method met the requirement for the assay.30 healthy broiler were choosed to study the residue elimination of tilmicosin.All of broiler were admininstered tilmicosin in drinking water(0.75g/L)and successive administration for 3 days.Then six treated broiler were slaughtered at 6h,1d,3d,9d and 13 d after administration.Muscle,fat,liver and kidney tissues were sampled and analyzed by HPLC.The results showed that the absorption of tilmicosin was quickly,the duration time of tilmicosin residual concentration in pig tissues was as follow:liver> kidney> adipose> muscle,and the residue concentration in liver is highest.Therefore,it suggests that liver can be treated as a target tissue for monitoring tissues inbroiler.The ministry of agriculture of the People's Republic of China and the European Agency for the Evaluation of Medicinal Products(EMEA)for Veterinary Medicine provide the maximum residue limits about muscle?adipose?kidney and liver in broiler,with the responding values were respectively 75?g/kg,75?g/kg,250?g/kg,1000?g/kg.According to the regulation,the withdrawal time of tilmicosin in broiler was calculated by WT1.4 software.The results showed that the withdrawal time of tilmicosin in muscle?kidney?liver?adipose was 8.99d?11.98 d and 12.25 d respentively.Therefore,it suggests that the withdrawal time of tilmicosin in broiler was 13 d after admininstered 10% tilmicosin in drinking water(0.75g/L).