超高效液相色谱-串联质谱法测定豆芽中4-氯苯氧乙酸钠残留量的不确定度评定

Uncertainty evaluation for determination of sodium 4-chlorophenoxyacetate residue in bean sprouts by ultra performance liquid chromatography-tandem mass spectrometry

目的评定超高效液相色谱-串联质谱法测定豆芽中4-氯苯氧乙酸钠残留量的不确定度。方法通过构建不确定度评定的数学模型,分析不确定度分量的来源,对试样称量、前处理过程、标准物质配制、标准工作曲线拟合及实验重复性、回收率等各分量加以量化和合成。结果豆芽中4-氯苯氧乙酸钠含量为59.44μg/kg,其测量扩展不确定度为3.6μg/kg (k=2),其中影响测量不确定度的主要因素是标准溶液配制和标准曲线拟合所引入的不确定度。结论在检测过程中应使用纯度较高的标准溶液,提高标准溶液配制的准确性,保证标准曲线的相关性符合规定。

Objective To evaluate the uncertainty of the residual amount of sodium 4-chlorophenoxyacetate in bean sprouts by ultra performance liquid chromatography-tandem mass spectrometry. Methods Mathematical model of uncertainty evaluation was constructed, the sources of uncertainty were analyzed, and various components were quantified and synthesized such as sample weighing, pretreatment process, standard material preparation, standard working curve fitting, experimental repeatability, and recovery rate. Results When the content of 4-chlorophenoxyacetate in bean sprouts was 59.44 μg/kg, and the expanded uncertainty was 3.6 μg/kg(k=2), the main factor affecting the measurement uncertainty was the uncertainty introduced by the standard solution preparation and standard curve fitting. Conclusion In the detection process, a standard solution of higher purity should be used to improve the accuracy of standard solution preparation and ensure that the correlation of the standard curve meets the requirements.