LC-MS法快速测定蜂蜜中甲硝唑地美硝唑和洛硝哒唑

Rapid Determination of Metronidazole, Dimetronidazole and Lonidazole in Honey by LC-MS

建立了液相色谱-串联质谱法(LC-MS)快速测定蜂蜜中甲硝唑、地美硝唑和洛硝哒唑的检测方法。以水为提取溶剂,加入适量甲醇,乙酸乙酯萃取,经浓缩、复溶、过滤,通过LC-MS法检测枣花蜂蜜中3种硝基咪唑类药物残留,以外标法定量。测定当加入甲硝唑量分别为2.5μg/kg、10.0μg/kg和50.0μg/kg时,回收率分别为85.2%、82.7%和81.0%,当加入地美硝唑量分别为5.0μg/kg、20.0μg/kg和100.0μg/kg时,回收率分别为92.3%、88.4%和88.7%,当加入洛硝哒唑量分别为5.0μg/kg、20.0μg/kg和100.0μg/kg时,回收率分别为92.3%、73.9%和76.6%。甲硝唑、地美硝唑、洛硝哒唑检出限分别为0.1μg/kg、0.2μg/kg和0.2μg/kg。结果表明:该方法稳定性好,准确度高,操作简单、快速,可以满足低残留量的检测要求。

A rapid method for the determination of metronidazole, dimetronidazole and lornidazole in honey by liquid chromatography-tandem mass spectrometry(LC-MS) was established. Three nitroimidazole residues in jujube honey were determined by LC-MS with water as extraction solvent, methanol and ethyl acetate as extraction solvent, followed by concentration, resolving and filtration, the residues were quantified by external standard method.The recoveries were 85.2%,82.7% and 81.0% when adding metronidazole were 2.5μg/kg, 10.0μg/kg and 50.0μg/kgrespectively. When adding metronidazolewere 5.0μg/kg, 20.0μg/kg and 100.0μg/kgrespectively, the recoveries were 92.3%, 88.4% and 88.7%. When adding metronidazole(RNZ) was 5.0μg/kg, 20.0μg/kg and 100.0μg/kgrespectively,the recoveries were 92.3%,73.9% and 76.6%. The detection limits of metronidazole, dimetronidazole and lornidazole were 0.1μg/kg, 0.2μg/kg and 0.2μg/kgrespectively,the results showed that the method was stable, accurate, simple and fast, and could meet the detection requirements of low residues.