电感耦合等离子体质谱法测定大米中总砷、镉和铅含量的不确定度评估

Uncertainty evaluation for determination of total arsenic, cadmium and lead content in rice by inductively coupled plasma mass spectrometry

中文关键词:  电感耦合等离子体质谱法  不确定度  大米  总砷  镉  铅

英文关键词:inductively coupled plasma mass spectrometry  uncertainty  rice  total arsenic  cadmium  lead

中文摘要:

      目的 评估电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)测定大米中总砷、镉和铅含量的不确定度。方法 依据GB 5009.268—2016, 利用电感耦合等离子体质谱法测定大米中总砷、镉和铅含量, 按照CANS-GL 006: 2018的评估方法, 建立测量结果的不确定度评估模型, 分析不确定度来源, 计算不确定度分量并合成。结果 大米中总砷、镉和铅含量分别为0.0913、0.0793、0.0265 mg/kg, 扩展不确定度分别为0.00828、0.00484、0.00322 mg/kg (k=2)。结论 影响总砷、镉和铅不确定度的主要因素为标准曲线拟合, 其次为标准溶液配制过程, 而重复测定、加标回收和样品制备可忽略不计。

英文摘要:

      Objective To evaluate the uncertainty of determination of total arsenic, cadmium and lead in rice by inductively coupled plasma mass spectrometry (ICP-MS). Methods According to GB 5009.268—2016, the contents of total arsenic, cadmium and lead in rice were determined by inductively coupled plasma mass spectrometry. According to the CANS-GL 006: 2018, a mathematical model for uncertainty evalution was established, the source of uncertainty was analyzed, and the component of uncertainty was quantified and synthesized. Results The content of the total arsenic, cadmium and lead in rice were 0.0913, 0.0793 and 0.0265 mg/kg, respectively, and the expanded uncertainties were 0.00828, 0.00484 and 0.00322 mg/kg (k=2). Conclusion The main factor influencing the uncertainty of total arsenic, cadmium and lead is the standard curve fitting, followed by the standard solution preparation process, while repeatability, recovery rate experiment and sample preparation are negligible.