火焰原子吸收光谱法测定汽油中锰的不确定度评价

Uncertainty Evaluation of the Determination of Manganese Content in Gasoline by Flame Atomic Absorption Spectrometry

摘要: 分析与讨论了汽油中锰含量测定过程中的不确定度来源，并对各个不确定度分量进行量化与合成，计算出火焰原子吸收光谱法测定汽油中锰含量的相对合成不确定度为0.083（锰含量约为10 mg/L），扩展不确定度U为1.8 mg/L（置信水平为95%，k=2）. 比较各个不确定度分量可知，测定结果的不确定度主要源自标准工作溶液的最小二乘法拟合.

Abstract: The uncertainty resources of the determination of manganese content in gasoline were analyzed. Every component of the uncertainty was quantified and compounded. The results showed that when the content of manganese in the gasoline sample is about 10 mg/L, the relative uncertainty is 0.083, and the expanded uncertainty is 1.8 mg/L (the confidence level: 95%, the coverage factor k=2). Comparing the uncertainty components, it shows that the main uncertainty source is from the curve fitting process using least square method.