电感耦合等离子体串联质谱法测定农产品中硒含量的不确定度评定

Evaluation of Uncertainty in Determination of Selenium Content in Agricultural Products by Inductively Coupled Plasma Tandem Mass Spectrometry

目的:评定电感耦合等离子体串联质谱法测定农产品中硒含量的不确定度。方法:以海南大米为研究对象,结合标准物质的测定分析测定硒含量过程中不确定度的来源;通过统计方法,从试样测量的重复性、曲线拟合等方面计算各分量的不确定度及扩展不确定度。结果:样品中硒含量测定结果为16.31 mg·kg^(-1),扩展不确定度U=1.51 mg·kg^(-1)(k=2),p=95%。结论:样液硒浓度测量和测量重复性是农产品中硒含量测定不确定度的主要来源。

Objective:To evaluate the uncertainty of inductively coupled plasma tandem mass spectrometry for the determination of selenium content in agricultural products.Method:The source of uncertainty in the determination of selenium content in agricultural products,combined with the determination and analysis of standard substances;calculate the uncertainty and expanded uncertainty of each component through statistical methods,including the repeatability of sample measurements and curve fitting.Result:The selenium content in the sample was determined to be 16.31 mg·kg^(-1),with an expanded uncertainty of U=1.51 mg·kg^(-1)(k=2)and p=95%.Conclusion:Measurement repeatability is the main source of uncertainty in the determination of selenium content in agricultural products.