Studies On Method Of HPLC-FLD And Residue Depletion Of Amoxicillin And Ampicillin In Plasma, Eggs And Excrement Of Hens

Using JingHai yellow chickens as experimental material in this study.The study on elimination of residues of AMO and AMP has been conducted in plasma,eggs and excrement of laying hens, After the laying hens orally administered successively AMO of25.0mg·kg-1·b.w.-d-1,50.0mg·kg-1-b.w.-d-1and AMP60.0mg·kg-1·b.w.-d-1,120.0mg·kg-1·b.w.·d-1of body weight once every day for5days, 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 study on HPLC-FLD method and residue depletion of AMO and AMP was conducted in plasma of laying hens. AMO and AMP were extracted from plasma of laying hens with acetonitrile. The extract solution was extracted in saturated methylene chloride. The supernatant was reacted with salicylide under acidic and boiling conditions. Linear regression curves were obtained over concentration ranges of5.0ng·mL-1～S000ng·mL-1for AMO and AMP with correlation coefficients of0.9999and0.9996,respectively. At the fortified levels of5～125ug·mL-1for AMO and AMP, the recovery values of plasma are all higher than74.72%, the relative standard deviations are all lower than10.66%. Limits of detection (LOD) were2.0ng·mL-1and1.0ng·mL-1for AMO and AMP, Limits of quantitation (LOQ) were5.0ng·mL-1and2.5ng-mL"’ for AMO and AMP. After the laying hens orally administered successively AMO of25.0mg·kg-1·b.w.·d-1,50.0mg·kg-1·b.w.-d-1and AMP60.0mg·kg-1·b.w.-d-1,120.0mg·kg-1·b.w.·d-1of body weight once every day for5days, respectively. At administration time, residues of AMO and AMP in plasma have a rise trend faster, the maximum concentration of AMO and AMP was all detected at5day in the plasma; At the withdrawal time, the residues of AMO and AMP in plasmawere eliminated faster, concentrations of AMO was all below the LOD at2days for the plasma, at3days for AMP.2、A study on HPLC-FLD method and residue depletion of AMO and AMP was conducted in eggs of laying hens. AMO and AMP were extracted from eggs of laying hens with acetonitrile. The extract solution was extracted in saturated methylene chloride. The supernatant was reacted with salicylide under acidic and heating conditions. Linear regression curves were obtained over concentration ranges of5.0ng·mL- 800.0ng·mL-1for AMO and AMP with correlation coefficients of0.9998and0.9999. At the fortified levels of5.0～125.0ng·g-1for AMO and AMP, the recovery values of eggs are all higher than78.30%, the relative standard deviations(RSD) are all lower than7.25%. Limits of detection (LOD) were1.2ng·g-1and0.5ng·g-1for AMO and AMP, Limits of quantitation (LOQ) were3.9ng·g-1and1.2ng·g-1for AMO and AMP. After the laying hens orally administered successively AMO of25.0mg·kg-1(b.w.·d-1,50.0mg·kg-1·b.w.·-d-1and AMP60.0mg·kg-1·b.w.·d-1,120.0mg·kg-1·b.w.·d-1of body weight once every day for5days, respectively.At administration time, residues of AMO and AMP in the albumen, yolk and whole eggs have a rise trend rapidly; the maximum concentration of AMO and AMP in albumen was detected at lday after withdrawal of medication. At the withdrawal time, the maximum concentration of AMO and AMP in the yolk was detected at2day. The residues of AMO and AMP in eggs were eliminated faster, concentrations of AMO and AMP was all below the LOD at11days for whole egg. With the reference of the criterions of the maximum residue limits (MRLs) of Japan positive list in eegs about AMO and AMP, this research suggested when the laying hens orally administered successively AMO solution of25.0mg·kg-1and50.0mg·kg-1of body weight once every day for5days, the withdrawal time should be5-day; when the laying hens orally administered successively AMP of60.0mg·kg-1and120.0mg·kg-1of body weight once every day for5days, the withdrawal time should be6-day and7-day3、A study on HPLC-FLD method and residue depletion of AMO and AMP was conducted in excreta of laying hens. AMO and AMP were extracted from excreta of laying hens with acetonitrile. The extract solution was extracted in saturated methylene chloride. The supernatant was reacted with salicylide under acidic and heating conditions. Linear regression curves were obtained over concentration ranges of0.1ug·mL-250.0μg·mL-1for AMO and AMP with correlation coefficients of0.9998. At the fortified levels of5.0～125.0μg·g-1for AMO and AMP, the recovery values of excreta are all higher than74.72%, the relative standard deviations are all lower than10.60%. Limits of detection (LOD) were3.0ng·g-1and1.2ng·g-1for AMO and AMP, Limits of quantitation (LOQ) were6.0ng·g-1and3.5ng·g-1for AMO and AMP. After the laying hens orally administered successively AMO of25.0mg·kg-1·b.w.·d-1,50.0mg·kg-1·b.w.·d-1and AMP60.0mg·kg-1·b.w.·d-1,120.0mg·kg-1·b.w.·d-1of body weight once every day for5days, respectively At administration time, residues of AMO and AMP in excreta have a rise trend rapidly; the maximum concentration of AMO in excreta was detected at4day, AMP was detected at5days. At the withdrawal time, the residues of AMO and AMP in excreta were eliminated faster, concentrations of AMO was below the LODs at5days and7days for the group (25.0mg·kg-1) and group (50.0mg·kg-1), concentrations of AMP was below the LOD at7days.