鳗鱼、饲料中恩诺沙星残留的测定及真假阳性辨别

Determination of Residual Enrofloxacin in Eel or Feed and Distinguish the False from the Genuine

采用反相高效液相色谱法(RP HPLC),测定鳗鱼、饲料中的恩诺沙星药物残留.在WatersNova PakC18柱上,用荧光检测器,激发波长280nm;发射波长450nm.流动相为5mmol/LNaH2PO4溶液-乙腈溶液(体积比为70∶30),磷酸调pH值为2.7,流速1.2mL/min,柱温40℃.在鳗鱼、饲料中的最低检测限分别达到1μg/kg和2μg/kg,标准曲线在30～500ng/mL线性范围内相关系数达0.9997.在3种浓度水平对鳗鱼组织和饲料中的3种浓度进行回收率测定,其回收率在76%～98%之间;变异系数RSD小于8%,符合痕量测定要求[1].还对如何辨别真假阳性进行特别介绍.

A RP-HPLC method with a fluorescence detector was established to determine enrofloxacin residues in eel or feed. The chromatographic conditions were: Waters Nova-Pak C18(3.9 mm i.d. ×150 mm, 4 μm)used for column(at 40 ℃)with 5mmol/L phosphate buffer (pH2.7)-acetonitrile(70∶30,v/v)as mobile phase, flow rate 1.2 mL/min, the excitation wavelength of 280 nm and an emission wavelength of 450 nm. The detection limit for eel and feed was 1 μg/kg and 2 μg/kg respectively. The calibration graphs were linear from 30～500 ng/mL, and correlation coefficients r=0.9997. At the level of 10 μg/kg, 50 μg/kg and 100 μg/kg, the recoveries were 76%～98%,which are satisfactory as residues in trace test. RSD<8% meets the requirement too. This title specially introduced how to distinguish the false from the genuine.