液质联用法测定蔬菜中新烟碱类农药的不确定度评定

Uncertainty Evaluation for Determination of Neonicotinoid Pesticide Residues in Vegetables by Liquid Chromatography Tandem Mass Spectrometry

为评定液相色谱串联质谱法测定蔬菜中新烟碱类农药的不确定度,通过改进的QuEChERS-高效液相色谱串联质谱法测定叶用莴苣中3种新烟碱类农药(噻虫嗪、吡虫啉、啶虫脒)的含量,并建立数学模型,分析不确定度的来源并进行量化。结果表明,当蔬菜中噻虫嗪、吡虫啉、啶虫脒质量分数分别为0.047、0.054、0.051 mg/kg,在95%的置信区间下,标准合成不确定度分别为0.0034、0.0040、0.0051 mg/kg,扩展不确定度分别为0.0068、0.0080、0.0100 mg/kg(k=2)。影响检测结果不确定度的主要因素为标准曲线拟合、仪器设备状态、重复性及回收率,因此,要对这几个方面严加控制,为液相色谱串联质谱法测定蔬菜中新烟碱类农药残留检测结果的评价提供参考。

To evaluate the uncertainty of liquid chromatography tandem mass spectrometry for the determination of neonicotinoid pesticides in vegetables,the improved QuEChERS high-performance liquid chromatography tandem mass spectrometry method was used to measure the content of three neonicotinoid pesticides(thiamethoxam,imidacloprid,and acetamiprid)in lettuce leaves,and a mathematical model was established to analyze the sources of uncertainty and quantify them.The results showed that when the mass fractions of thiamethoxam,imidacloprid,and acetamiprid in vegetables were 0.047,0.054,0.051 mg/kg,respectively,the standard synthetic uncertainties were 0.0034,0.0040,0.0051 mg/kg,and the extended uncertainties were 0.0068,0.0080,0.0100 mg/kg,respectively,at a 95% confidence interval(k=2).The main factors affecting the uncertainty of detection results were standard curve fitting,instrument status,repeatability,and recovery rate.We need to strictly control these aspects.This study provided a reference for the evaluation of the detection results of neonicotinoid pesticise residues in vegetables by liquid chromatography tandem mass spectrometry.