气相色谱-质谱法测定柑橘中丙溴磷的不确定度评定

目的建立气相色谱-质谱法(gas chromatography-tandem mass spectrometry, GC-MS/MS)测定柑橘中丙溴磷不确定度的评定模型。方法根据CNAS-GL006:2018《化学分析中不确定度的评估指南》,分析气相色谱-质谱法测定柑橘中丙溴磷的不确定度来源,建立科学的数学模型并量化各个影响分量,得到丙溴磷测定结果的拓展不确定度。结果气相色谱-质谱法测定丙溴磷时,对于结果的不确定度影响顺序为:标准曲线的稀释配制过程>线性拟合>样品的前处理过程,当柑橘中丙溴磷含量为0.15 mg/kg时,其拓展不确定度为0.04 mg/kg(k=2)。结论该评估模型为气相色谱-质谱法测定丙溴磷,内标法进行定量时的不确定度的评估提供了参考依据。

Uncertainty evaluation for the determination of profenofos in citrus by gas chromatography-tandem mass spectrometry

Objective To establish a evaluation model of uncertainty for determination of profenofos in citrus by gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods According to the CNAS-GL006:2018 Evaluation guide for uncertainty in chemical analysis, the source of uncertainty for determination of phosphorus bromide in citrus by gas chromatography-mass spectrometry was analyzed, and a scientific mathematical model was established to quantify the influence components. Results The order of influence of uncertainty on the result of determination of profenofos by GC-MS/MS was as follow: The dilution preparation process of the standard curve> linear fitting>the pre-treatment process of sample. When the content of profenofos in citrus was 0.15 mg/kg, the extension uncertainty was 0.04 mg/kg (k=2). Conclusion The evaluation model provides a reference for the evaluation of uncertainty in quantitative analysis in the determination of profenofos by GC-MS/MS.