同位素稀释液相色谱-串联质谱法测定鱼肉粉中五氯酚钠的不确定度评定

Uncertainty evaluation in determination of sodium pentachlorophenol in fish powder by isotope dilution coupled with liquid chromatography-tandem mass spectrometry

采用同位素稀释液相色谱-串联质谱法测定鱼肉粉中的五氯酚钠含量,依据JJF 1059.1—2012《测定不确定度评定与表示》等不确定度评定的相关标准及规范,对测定结果的不确定度进行评定。分别对标准溶液配制、样品称量、标准曲线拟合、测量重复性等影响不确定度的分量进行分析。结果表明,不确定度的主要来源是标准溶液的配制、样品测定重复性和标准曲线拟合。当包含因子k=2时,同位素稀释液相色谱-串联质谱法测定鱼肉粉中五氯酚钠的含量为24.4μg/kg,在95%的置信区间下,扩展不确定度为1.0μg/kg。该方法为科学评价实验结果的准确性提供依据,为评定其他相关检测方法的不确定度提供参考。

According to JJF 1059.1—2012"Evaluation and expression of measurement uncertainty",a mathematical model of uncertainty evaluation of sodium pentachlorophenol in fish powder was established by isotope dilution coupled with liquid chromatoc-tandem mass spectrometry,and the sources of uncertainty affecting the measurement results were analyzed and evaluated.The components affecting the uncertainty of standard solution preparation,sample weighing,standard curve fitting and measurement repeatability were analyzed respectively.The contents of sodium pentachlorophenol in fish powder were 24.4μg/kg and the extended uncertainty was 1.0μg/kg(k=2)under 95%confidence interval.The evaluation results show that the main source of uncertainty in the determination of sodium pentachlorophenol in fish powder by liquid chromatography-tandem mass spectrometry were as follows:the allocation of standard solution,the fitting of standard curve and the repeatability of measurement.This method provides a basis for scientific evaluation of the accuracy of experimental results and a reference for evaluating the uncertainty of other related detection methods.