为了评定用石墨炉原子吸收法测定烟用香精中As、Pb的不确定度,建立了其测量不确定度评定的数学模型和因果关系图,确定了其各测量不确定度的分量。结果表明:该测量不确定度的主要来源为样品的重复性和测定的样品浓度;As、Pb测量结果的标准不确定度分别为0.04、0.02 mg/kg;取包含因子k=2,在95%的置信水平下,As、Pb测量结果的扩展不确定度分别为0.08、0.04 mg/kg。 In order to evaluate the uncertainty of determination of As and Pb in tobacco flavors by graphite furnace atomic absorption spectrometry, a mathematical model and a causal relationship diagram of evaluating the uncertainty of the measurement were established, and the components of each measurement uncertainty were determined. The results show that the main sources of this uncertainty are the repeatability of the sample and the concentration of the sample. The standard uncertainty of the As and Pb measurements are 0.04 and 0.02 mg / kg, respectively. The inclusion of k = 2 and 95 % Confidence level, the expanded uncertainty of As and Pb measurements were 0.08 and 0.04 mg / kg, respectively.