电感耦合等离子体质谱法测定竹荪中r铅、 镉、 砷的不确定度评定

摘要

采用电感耦合等离子体质谱法(ICP-MS)测定竹荪中铅(Pb)、 镉(Cd)和砷(As),分析测定过程,确定不确定度来源,建立不确定度评定数学模型.本方法测定不确定度的主要来源为5个方面:重复测量、 标准溶液配制、 样品称量、 定容体积、标准曲线拟合.对单个不确定度分量进行合成和扩展,建立ICP-MS测定竹荪中铅、 镉和砷的不确定度评定方法.结果表明:Pb含量为(1.02±0.1)mg/kg,k=2;Cd含量为(0.17±0.03)mg/kg,k=2;As含量为(0.59±0.05)mg/kg,k=2.本研究为电感耦合等离子体质谱法测定竹荪中重金属元素的不确定度评定和质量控制提供参考.%The heavy metals of lead, cadmium and arsenic were measured by inductively coupled plasma mass sprctrometry ( ICP-MS). By analyzing the determination process to find the uncertainty source, the mathematical model was established, the single synthesis was combined and expanded, the evaluation method of uncertainty was established. The main uncertainties were attributed to five sources, namely measurement repeatability, preparation of standard solutions, sample weighing, sample volume size and curve fitting in decreasing order of uncertainty contribution. The results showed that the content of lead in dictyophora was (1. 02±0. 1) mg/kg, k=2, cadmium was (0. 17±0. 03) mg/kg, k=2, and the content of arsenic was (0. 59±0. 05) mg/kg, k=2. This research provided reference for the uncertainty evaluation and quality control for measurement of heavy metals in dictyophora by ICP-MS.