Studies On HPLC-FLD Method For Determination And Depletion Of Amoxicillin And Ampicillin Residues In Chicken Tissues

A high performance liquid chromatography with fluorescence detection (HPLC-FLD) method for simultaneous determination of the residues of amoxicillin (AMO) and ampicillin (AMP) in chicken tissues (muscle、liver and kidney) had been developed and validated, using Jinghai yellow broiler as experimental material in this study. Further more, the study on elimination of residues of AMO and AMP has been conducted in chicken tissues, after the Jinghai yellow broiler orally administered successively of30.0mg/kg-b.w.,60.0mg/kg of AMO of body weight once every day for7days, respectively; and orally administered successively of120.0mg/kg,240.0mg/kg of AMP of body weight once every day for7days, respectively. The study not only provides basis for the proper use of AMO and AMP, but also establishing withdrawal time and standards of determination of AMO and AMP in foodstuffs of animal origin and developing pollution-free livestock and poultry products. The main results were as follows:1. A HPLC-FLD method was developed for simultaneous determination of AMO and AMP in chicken muscle, liver and kidney was developed. The calibration curve showed good linearity of the two veterinary drug within the concentrations of25～1000μg/kg with the determination coefficient R2>0.9997. At the fortified levels of5～100μg/kg, the recovery values of AMO in chicken muscle、liver and kidney are higher than70.57%、68.65%and69.65%, respectively. The relative standard deviations (RSD) are all less than9.48%、10.53%and10.54%, the intra-day RSD are all less than6.36%、7.22%and8.43%, the inter-day RSD are all less than12.36%、12.47%and11.22%. The LOD and LOQ for AMO in the tissues are5μg/kg and13μg/kg, AMP are3.5μg/kg and10μg/kg.2. A study on HPLC-FLD method and elimination of residues of AMO was conducted in chicken muscle, liver and kidney. The calibration curve showed good linearity within the concentrations of25～1000μ/kg with the determination coefficient R2=0.9997. When the fortified levels at5～100μg/kg, the recovery values of AMO in chicken muscle、liver and kidney are higher than73.64%、72.82%and74.93%, RSD are all less than9.63%,9.50%and8.83%, the intra-day RSD are all less than8.23%,9.04%and8.84%, the inter-day RSD are all less than13.93%,14.37%and13.37%, respectively. The LOD and LOQ for AMO in the tissues are5μg/kg and13μg/kg. We researched the law of AMO residues elimination after the two groups jinghai yellow broiler chickens were orally administered with AMO of30mg/kg and60mg/kg of body weight once every day for7days, respectively. After a withdrawal time of4h, the concentration of AMO was the highest. At the withdrawal time of day3, the concentration of AMO in all tissues depleted rapidly. Residues of AMO in chicken tissues were all lower than MRLs (50μg/kg) at5th withdrawal day. Residues of AMO in chicken muscles and liver were all lower than the LODs (5.0μg/kg) at7th withdrawal day. At9th, the AMO resdues were all lower than the LODs. With the reference of the criterions of the maximum residue limits (MRLs) of China and European Medicines Agency (EMEA) in chicken muscles about AMO, we used the WT1.4software calculated the withdral time are2.82d and3.47d, respectively. So we suggested that when the yellow feather broiler orally administered successively AMO of30mg/kg and60mg/kg of body weight once every day for7days respectively, the withdrawal time should be3d and4d.3. A study on HPLC-FLD method and elimination of residues of AMP was conducted in chicken muscle, liver and kidney. The calibration curve showed good linearity within the concentrations of25～11000μg/kg with the determination coefficient R2=0.9998. When the fortified levels at3～100μg/kg, the recovery values of AMP in chicken muscle、liver and kidney are higher than76.53%、75.31%and78.76%, RSD are all less than8.82%、10.20%and9.29%, the intra-day RSD are all less than8.77%、9.21%and8.99%, the inter-day RSD are all less than12.78%、11.64%and12.54%, respectively. The LOD and LOQ for AMP in the tissues are3.5μg/kg and10μg/kg. We researched the law of AMP residues elimination after the two groups jinghai yellow broiler chickens were orally administered with AMP of120mg/kgand240mg/kg of body weight once every day for7days, respectively. After a withdrawal time of4h, the concentration of AMP was the highest. At the withdrawal time of day3, the concentration of AMP in all tissues depleted rapidly. Residues of AMP in chicken tissues were all lower than MRLs (50μg/kg) at5th withdrawal day. Residues of AMP in chicken muscles and liver were all lower than the LODs at7th withdrawal day. At9th, the AMP resdues were all lower than the LODs. With the reference of the criterions of the MRLs of China and European Medicines Agency (EMEA) in chicken muscles about AMP, we used the WT1.4software calculated the withdral time are3.82d and4.80d, respectively. So we suggested that when the yellow broiler chickens orally administered successively AMP of120mg/kg and240mg/kg of body weight once every day for7days respectively, the withdrawal time should be4d and5d.