液相原子荧光测定裙带菜中无机砷含量的不确定度评定

Evaluation of Uncertainty in Determination of Inorganic Arsenic in Wakame by Liquid Phase-Atomic Fluorescence Spectrometry

采用液相原子荧光测定裙带菜中无机砷含量,评定了测定过程的不确定度。通过对重复性实验引入的不确定度、标准物质和配制过程引入的不确定度、标准曲线拟合引入的不确定度、试样的称量质量引入的不确定度、仪器引入的不确定度以及定容体积引入的不确定度的计算,结果表明标准曲线的拟合是影响不确定度的主要因素,其次是重复实验和五价砷标样配制过程引入的不确定度。对某裙带菜待测样品,无机砷含量为0.080 5 mg/kg时,扩展不确定度为0.006 7 mg/kg。

Liquid Phase-Atomic Fluorescence is used to evaluate uncertainty of wakame,and content of inorganic arsenic is to be quantified.The uncertainty,which was introduced by repeatability measurement,reference materials,preparation process,standard curve fitting and sample weighing quality,which have been calculated.The experiment suggested that standard curve fitting was the main fact for influencing the uncertainty,and repeatability measurement and preparation process of As(V)standard substance were following by.Furthermore,the content of inorganic arsenic in wakame was 0.080 5 mg/kg,and the expand uncertainty was 0.006 7 mg/kg.