氧氟沙星在肉鸡体内残留的研究

Studies on Residues of Ofloxacin in Broiler Chicken Tissues

建立了氧氟沙星在肉鸡组织内残留的高效液相色谱分析法。采用荧光检测器，激发波长278nm，发射波长445nm。色谱柱为Hypersil BDS—C18，柱温40℃；以磷酸（三乙胺调pH至2．5）-乙腈（86：14）为流动相，流速1．0mL／min；进样量为20μL。氧氟沙星在肌肉、肝脏和肾脏中的平均回收率分别为96．3％、87．5％和76．4％，检测限为10ng／g，在10～1000ng／mL浓度范围内，氧氟沙星的峰面积与其浓度呈良好的线性相关，达到了氧氟沙星残留分析的要求。利用建立的方法对氧氟沙星在肉鸡体内的残留消除规律进行了研究，以1L水添加500mg的剂量，对120只肉鸡连续给药5d，对不同停药时间所取肌肉、肝脏和肾脏样品中的药物残留进行分析。结果表明，氧氟沙星在肉仔鸡组织中的残留消除速度较为缓慢，至休药23d时，仍可在肝脏和肾脏分别检出39和35μg/kg的氧氟沙星残留。在本实验的条件下，建议氧氟沙星临床休药期以25d为宜。

A reversed -phase high performance liquid chromatographic method has been developed for the determination of ofloxaein residues in chicken tissues. After being extracted with phosphate buffer, ofloxaein was analyzed by HPLC （Hypersil BDS-C18） and detected by FLD（ λex = 278 nm, λem =445 nm）. The mobile phase was aeetonitrile-phosphorie aeid/triethylamine（ 14： 86）. The linear range was 10 ～ 1 000 ng/mL （r =0. 9992）. The average recovery of ofloxaein was 96.3% ,87.5% and 76.4% in muscle,liver and kindney, respectively.The minimal detectable concentration of ofloxacin was 10 ng/g. This method can meet the demand of residues determination of ofloxacin in various chicken tissues. 120 broiler chickens were administered ofloxacin at a 500 g/L by drinking dosage of for 5 d. Results of this experiment showed that the depletion of ofloxacin in muscle was the concentration of ofloxacin was declined lower than LOD at the 19 d. However, the depletion of drugs in fast, liver and kidney were slower, the concentration of ofloxacin were 39 μg/kg and 35 μg/kg in liver and kidney respectively. A 25-day of withdrawal time was recommended.