固相萃取-同位素稀释/超高效液相色谱-串联质谱法测定蜂蜜中甲硝唑、二甲硝咪唑和洛硝哒唑

建立超高效液相色谱-串联质谱法测定蜂蜜中甲硝唑、二甲硝咪唑、洛硝哒唑残留量的方法。样品采用乙酸乙酯提取，同位素稀释，混合阳离子交换柱净化，经C₁₈色谱柱(3.0 mm×100 mm,1.7μm)分离后，在多反应监测模式下测定，内标法定量。甲硝唑、二甲硝咪唑、洛硝哒唑在1.0～100.0 ng/mL质量浓度范围内线性关系良好，测定结果相对标准偏差为1.6%～3.7%(n=6)，平均加标回收率为95.0%～101.4%，能有效降低基质干扰。该方法操作简便，结果准确，普遍适用于蜂蜜中甲硝唑、二甲硝咪唑、洛硝哒唑的测定。

Determination of Metronidazolem,Dimetridazole and Ronidazole in Honey by On-line Solid-phase Extraction Coupled to Isotope Dilution-Ultra-high Performance Liquid Chromatography-Tandem Mass Spectrometry

In this study, we established a method for the determination of metronidazolem, dimetridazole and ronidazole in honey by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The analytes were extracted from samples, purified using a cation exchange cartridge, separated on a C18 (3.0 mm × 100 mm, 1.7 μm) chromatographic column, detected in the multiple reaction monitoring (MRM) mode, and quantitated by an internal standard method. Metronidazolem, dimetridazole and ronidazole were separated well and their calibration curves were linear in the concentration range of 1.0–100.0 ng/mL. The relative standard deviation for replicate determinations was 1.6%–3.7% (n = 6), and the average recoveries for spiked samples ranged from 95.0% to 101.4%. This method has the advantages of low matrix interference, simple operation and high accuracy, an is suitable for the determination of the residues of metronidazolem, dimetridazole and ronidazole in honey.