超高效液相色谱-串联质谱法测定蔬菜水果中的百草枯和敌草快残留

Determination of paraquat and diquat in vegetables and fruits by ultra performance liquid chromatography tandem mass spectrometry

中文关键词:  超高效液相色谱-三重四极杆串联质谱法  百草枯  敌草快  蔬菜  水果

英文关键词:ultra performance liquid chromatography tandem mass spectrometry  paraquat  diquat  vegetables  fruits

中文摘要:

      目的 建立超高效液相色谱-串联质谱法快速测定6种蔬菜和水果以及玉米、香菇等其他植物源性样品中百草枯和敌草快的分析方法。方法 样品先以0.5 mol/L HCl浸泡酸化5 min, 再以10 mL甲醇-0.5 mol/L HCl(1:1, V:V)振荡提取10 min, 然后于80 ℃水浴中保温30 min, 提取液冷却后于5000 r/min离心5 min, 取上层清液过0.22 μm的滤膜, 直接上机测定。以20 mmol/L甲酸铵(pH=3)-乙腈为流动相, 经亲水色谱柱(hydrophilic interaction liquid chromatography, HILIC)进行分离后进行超高效液相色谱-三重四极杆串联质谱多反应监测模式分析, 内标法定量。结果 百草枯的检出限(limits of detection, LOD)、定量限(limits of quantitation, LOQ)分别为2.0、7.0 μg/kg, 敌草快的LOD、LOQ分别为1.5、8.0 μg/kg。考察了8种不同样品的基质效应, 其中敌草快在上海青和西芹中的基质效应较强, 需要以基质标准曲线进行定量校正。在10、50、100 μg/kg 3个浓度水平的加标回收试验下测得, 百草枯的回收率为74.6%~120.2%, 相对标准偏差(relative standard deviation, RSD)为0.9%~11.7%; 敌草快的回收率为76.6%~124.9%, RSD为2.0%~12.1%。结论 该方法操作简单, 快速。以内标法和基质匹配曲线定量, 结果准确, 适用于大量蔬菜水果样品中百草枯和敌草快的高通量分析和检测。

英文摘要:

      Objective To establish a rapid method for the determination of paraquat and diquat in 6 kinds of vegetables and fruits and other plant origin foodstuffs such as corn and lentinusedodes by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Methods The samples were soaked in 0.5 mol/L HCl for 5 min, then 10 mL MeOH-0.5 mol/L HCl (1:1, V:V) was added as extraction solvent, and shaken for 10 minutes. The sample tubes were heated in a water bath at 80 ℃ for 15 min. The sample tubes were cooled to room temperature and centrifuged at 5000 r/min for 5 min. At last, the supernatant was directly injected and analyzed by UPLC-MS/MS after filtered through a 0.22 μm membrane. Gradient elution was performed by using acetonitrile and 20 mmol/L ammonium formate (pH=3) as mobile phase. The mass spectrometric acquisition was carried out by means of multiple reaction monitoring (MRM) after separated by hydrophilic interaction liquid chromatography (HILIC) column. The method was quantified by internal standard method. Results The limits of detection (LOD) and limits of quantitation (LOQ) for the paraquat were 2.0 and 7.0 μg/kg, respectively. The LOD and LOQ of diquat were 1.5 and 8.0 μg/kg, respectively. The matrix effects of 8 different samples were investigated, among which diquat had stronger matrix effects in green grocery and celery, which needed to be quantified by matrix standard curve. At 3 concentration levels of 10, 50 and 100 g/kg, the recovery of paraquat was 74.6%~120.2%, and the relative standard deviation (RSD) was 0.9%~11.7%; the recovery of diquat was 76.6%~124.9%, and the RSD was 2.0%~12.1%. Conclusion This method is simple and fast and the results are accurate, which is suitable for the determination of paraquat and diquat in a large number of vegetable and fruit samples.