石墨炉原子吸收法测定面粉中铅的不确定度评定  

EVALUATION OF UNCERTAINTY IN MEASUREMENT FOR THE LEAD IN FLOUR BY GFAAS

作　　者：付文燕[1] 

机构地区：[1]北京市海淀区疾病预防控制中心,北京100080

出　　处：《现代预防医学》2009年第21期4160-4161,4166,共3页Modern Preventive Medicine

摘　　要：[目的]根据国家计量技术规范JJF1135-2005《化学分析测量不确定度评定》的要求,以石墨炉原子吸收法测定面粉中铅为例对测定结果的不确定度进行评定。[方法]对不确定度的主要来源包括称量的不确定度、标准物质的不确定度、体积的不确定度、标准曲线的不确定度及测量重复性引起的不确定度进行分析,并按数学模型计算出各不确定度分量、合成标准不确定度和扩展不确定度。[结果]得到石墨炉原子吸收法测定面粉中铅的不确定度,当面粉中铅含量为0.122mg/kg时,扩展不确定度为0.020mg/kg,结果表达为(0.122±0.020)mg/kg。[结论]正确选择前处理方法和熟练掌握前处理方法极其重要。定容体积、样品称量产生的不确定度非常小,对测量结果影响不大。[ Objective] To evaluate the uncertainty in measurement for the lead in flour by graphite furnace atomic absorption spectrometry, according to JJF 1135-2005 Evaluation of Uncertainty in Chemical Analysis Measurement. [ Methods] The main sources of the combined uncertainty were considered, such as the uncertainty of weight, uncertainty of volume, standard solution uncertainty, standard curve uncertainty, uncertainty induced by repeatability of measurements. The components of uncertainty and the combined uncertainty were calculated. [ Results] The concentration of the lead in flour was 0.122mg/kg, the expanded uncertainty was 0.020mg/kg, and the result of the measurement was （0.122 ± 0.020） mg/kg. [Conclusion] It is very important to correcdy choose pretreatment methods arid grasp these methods. The uncertainty induced when weighting is small, and it has a litde influence on the results.

关 键 词：石墨炉原子吸收法 铅 不确定度 

分 类 号：R155.5[医药卫生—营养与食品卫生学]