高效液相色谱法测定罗非鱼肌肉中硝基咪唑类多组分残留量

摘要

建立一种同时测定罗非鱼肌肉中甲硝唑、地美硝唑、奥硝唑、替硝唑、洛硝哒唑5种硝基咪唑类药物残留量的反相高效液相色谱法。水产品肌肉组织经匀浆,加氯化钠、磷酸氢二钾和乙酸乙酯振荡提取,取有机相浓缩,残余物加盐酸和乙酸乙酯溶解,正己烷去脂后过MCX柱,2%浓氨水甲醇溶液洗脱,色谱柱分离,以醋酸氨缓冲液-乙腈（86：14,V/V）为流动相,320nm紫外检测。结果显示：测定肌肉组织中5种硝基咪唑类药物的最低检测限均为1.0μg/kg。在2.0μg/kg的加样水平下,甲硝唑、地美硝唑、奥硝唑、替硝唑及洛硝哒唑在罗非鱼中的回收率分别为73.3%%、74.7%、62.9%、74.4%、80.1%;测定的标准偏差不大于10%。本方法简便、灵敏度高,准确度和精密度均符合我国农业部兽药残留分析方法的要求。%A high-performance liquid chromatography（HPLC） method was developed for the simultaneous analysis of 5 nitroimidazole multi-residues（metronidazole,dimetridazole,ornidazole,tinidazole and ronidazole） in tilapia muscle tissues.Samples were homogenized and extracted by added sodium chloride,monopotassium phosphate and ethyl acetate.Afterwards,the organic phase was recovered and condensed.Finally,the residue was dissolved in hydrochloric acid/ethyl acetate,defatted by liquid-liquid extraction with added n-hexane,cleaned up on an MCX column by elution with 2% ammonia/methanol,separated chromatographically using acetate buffer solution/acetonitrile（86：14,V/V） as the mobile phase and detected at 320 nm.The results revealed that the limits of detection for 5 nitroimidazoles were all 1.0 μg/kg.The average recoveries for metronidazole,dimetridazole,ornidazole,tinidazole and ronidazole at the spike level of 2.0 μg/kg were 73.3%%,74.7%,62.9%,74.4% and 80.1%,respectively with a RSD of less than 10%（n = 3）.This method is simple,sensitive,accurate,precise,and in line with the requirements the Ministry of Agriculture for veterinary drug residue analysis.