电感耦合等离子体质谱法测定食用植物油中重金属元素的不确定度评定

Uncertainty evaluation of determination of the heavy metals content in edible vegetable oil by inductively coupled plasma-mass spectrometry

目的评定电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定食用植物油中重金属元素铁和锰的含量不确定度。方法分析测定过程,找出不确定度来源,建立不确定度评定数学模型。对单个不确定度分量进行合成和扩展,建立电感耦合等离子体质谱法测定食用植物油中Fe、Mn的不确定度评定方法。结果食用植物油中Fe含量为(10.5±1.2)mg/kg,k=2;Mn含量为(5.81±0.99)mg/kg,k=2。结论影响结果不确定度的主要因素是样液浓度引入的不确定度,由拟合标准曲线求得样液浓度引入的不确定度分量最大,其次为样品回收率测试和测量重复性产生的分量,本研究为实验室内部质量控制提供了依据。

Objective To evaluate the uncertainty for determination of iron and manganese in edible vegetable oils by inductively coupled plasma mass spectrometry.Methods The determination process was analyzed,the sources of uncertainty were found,and the mathematical model of uncertainty evaluation was established.The single uncertainty component was synthesized and expanded to establish an uncertainty evaluation method for the determination of Fe and Mn in edible vegetable oil by inductively coupled plasma mass spectrometry.Results The content of iron in edible vegetable oil was(10.5±1.2)mg/kg,k=2,and the content of manganese was(5.81±0.99)mg/kg,k=2.Conclusion The main factors that affect the uncertainty of the results are the uncertainty introduced by the concentration of the sample solution,and the uncertainty introduced by sample concentration obtained by fitting standard curve has the greatest influence,followed by the sample recovery test and measurement repeatability.This study provides the basis for the internal quality control of the laboratory.