Development of RP-HPLC for determination of enrofloxacin and its metabolite in tissues of Chinese mitten-handed crab(Eriocheir sinensis) by RP-HPLC

The methods of reverse-phase high performance liquid chromatography(RP-HPLC) were developed to determine concentration of enrofloxacin(ENR) and ciprofloxacin(CIP) in muscle,hepatopancreas,spermary,ovary of Chinese mitten-handed crab(Eriocheir sinensis).The average recovery of ENR and CIP in four tissues is 70.5%±12.61%,70.25%±14.73%;The intra-day precision of ENR and CIP is(3.27%)±(0.84)%,(2.14%)±(0.68%),respectively;The inter-day precision is 5.38%±2.46%,3.48%±1.16%,respectively.The(lowest detected) limit of enrofloxacin in tissues is 0.02 μg/g,and ciprofloxacin is 0.004 μg/g.ENR was administered to E.sinensis in a single dose(10 mg/kg b.w.) following intramuscular administration.The Tmax,Cmax of ENR in four tissues are 1 h,(4.323)±(0.56) μg/g;1h,(6.042)±(0.72) μg/g;3 h,(2.381)±(0.43) μg/g;3 h,(2.101)±(0.29) μg/g,respectively,and the half-life of elimination in these tissues is 45.186 h,73.93 h,45.577 h,(38.081 h,) respectively.The method is fast,sensitive,precise and suitable to determine the concentrations of enrofloxacin and ciprofloxacin in Chinese mitten-handed crab,Eriocheir sinensis.