Studies On The Residues Of Chloramphenicol And Florfenicol In Crayfish Tissues

The elimination rule of chloramphenicol and florfenicol and the distribution of florfenicol amine in muscle and liver of crayfish in fresh water was studied in this paper.It estimated the therapeutic efficacy and the residual of chloramphenicol in crayfish and provided the preliminary experimental data of the drug holiday of florfenicol using the amount of florfenicoland florfenicol amine as its residual signal object.1Studies on the residues of chloramphenicol in crayfish tissuesA HPLC method was reported for the determination of crayfish tissue levels of chloramphenicol using methanol as solvent extraction and protein precipitation agent.Recoveries of chloramphenicol added to blank crayfish tissues at levels of4μg/kg,50μg/kg,400μg/kg were higher than88%,RSD was lower than6.90%.and the concentration of chloramphenicol were well lined within1μg/kg-400μg/kg. This method permitted the minimum detection limits of chloramphenicol in muscle and Hepatopancreas tissues at levels of1μg/kg.The results of elimination of laws showed that Crayfish solution with different concentrations of chloramphenicol for2hours soaking the Pharmacokinetic characteristics were significantly different between high dose(50μg/mL) and low dose (5μg/mL). In the high dose group,the elimination rate of chloramphenicol in muscle was much quicker than the rate of chloramphenicol in hepatopancreas.In the low dose group, the elimination rate of chloramphenicol in muscle was much slower than the rate of chloramphenicol in hepatopancreas. The elimination equations in the two groups in muscle were C(t)high=145.83e-0.0359xand C(t)low=15.086e-0.1243t, and the elimination half-lives were19.30h and5.58h, respectively. The elimination equations in the two groups in Hepatopancreas were C(t)high=135.68e-0.0927t and C(t)low=21.36e-0.0626t,and the elimination half-lives were7.48h and11.07h respectively.2Florfenicol and its metabolite florfenicol amine in the freshwater crayfish in the detection of residuesPharmacokinetics and residues of florfenicol and its main metabolite florfenicol amine following a continuous six-day dipping administration were evaluated in crawfish edible tissues. Muscle and hepatopancreas tissues of the selected crawfish were analyzed by high-performance liquid chromatography (HPLC). the results showed that The linear ranges were20-2000μg/kg of florfenicol and10-2000μg/kg of florfenicol amine,respectively. The detection limits were20ug/kg for Florfenicol and10μg/kg for florfenicol amine.the elimination rate of the drug was slower in hepatopancreas than in muscle. The elimination rate of the florfenicol in tissue was slower than that of the florfenicol amine. No florfenicol amine had been detected in muscle168hours after discontinuation.The concentration of the florfenicol amine in hepatopancreas and the florfenicol in muscle and hepatopancreas were both lower than LDL14days after discontinuation.The eliminate equations of the amount of florfenicol and florfenicol amine in muscle and hepatopancreas of crayfish in fresh water were y=690.78e-0.0135x and y=1778.7e-0.0111χ, The time when the concentration was100μg/kg in muscle and hepatopancreas were5.94d and10.8d in theory. Temperature was the main factor influencing the metabolism of antibacterials, so we suggest the withdrawal time of florfenicol for crawfish is270℃·d.