利用气液微萃取技术联用气相色谱-质谱法检测谷类中27种残留农药

Determination of 27 pesticides residues in grains by gas-liquid microextraction combined with gas chromatography-mass spectrometry

目的建立气液微萃取技术(gas-liquid microextraction,GLME)联用气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)快速检测谷类中的27种农药残留的方法。方法精确称量0.5 g谷类样品,用0.5 mL二氯甲烷溶剂超声萃取15 min,离心4 min后取上清液100μL,利用气液微萃取(GLME)对27种农残萃取、净化和浓缩,结合内标法确保结果的准确性。结果 27种农药在0.001~1.0mg/kg浓度范围内线性良好,相关系数在0.9990~0.9999,检出限为0.002~0.026 mg/kg,定量限为0.0007~0.086 mg/kg,平均回收率为71.2%~124.4%(n=3),相对标准偏差在0.2%~18.8%之间。结论本方法操作简便方便、准确度高、重现性好,适用于食品安全现场检测和快速检测,对于保障我国食品安全构建完整的食品安全检测体系具有重大意义。

Objective To establish a method for rapid detection of various pesticides in cereal grains by gas-liquid microextraction (GLME) and gas chromatography-mass spectrometry (GC-MS). Methods The 0.5 g cereal sample was accurately weighed and extracted with 0.5 mL dichloromethane solvent for 15 min, after 4 min centrifugation, 100 μL supernatant was taken and 27 kinds of residues were extracted, purified and concentrated by gas-liquid microextraction (GLME). The accuracy of the results was ensured by the internal standard method. Results The 27 kinds of pesticide had good linear relationships in the range of 0.001?1.0 mg/kg, and the correlation coefficients were 0.9990?0.9999. The limits of detection were 0.002?0.026 mg/kg and the limits of quantitation were 0.0007?0.086 mg/kg. The average recoveries were 71.2%?124.4%(n=3) with relative standard deviations of 0.2%?18.8%. Conclusion This method is simple and rapid, with high accuracy and good repeatability, which is suitable for rapid analysis or field-detection in the food safety industry. It is of great significance to build a complete food safety inspection system to ensure China's food safety.