气相色谱法测定能力验证样品果蔬汁中毒死蜱含量的不确定度评估

Uncertainty evaluation for determination of chlorpyrifos in the proficiency testing fruit juice by GC

采用气相色谱法测定果蔬汁中毒死蜱含量,对测定结果的不确定度进行了分析。建立了气相色谱外标法测定毒死蜱含量的数学模型,分析了不确定度的来源并给出了量化结果,计算出合成标准不确定度和扩展不确定度,分析结果表明,当果蔬汁中毒死蜱的含量为0.0172mg/kg,其扩展不确定度为0.0008mg/kg,k=2。

The determination uncertainty of chlorpyrifos in the proficiency testing fruit juice by GC was evaluated.The mathematical models were established to evaluate the uncertainty of quantitative results by GC based on the external standard method.Each source and uncertainty component was analyzed,and the combined expanded uncertainty was measured.The expanded uncertainty was 0.0008 mg/kg（k=2）while the content of chlorpyrifos in the fruit juice was 0.0172 mg/kg.