冷原子吸收法测定汽车制动摩擦衬片中汞含量的不确定度

Uncertainty of Mercury Content in Automobile Brake Lining by Cold Atomic Absorption Spectrometry

采用冷原子吸收测汞仪对汽车制动摩擦衬片中的汞元素进行定量分析,参照GB/T 27418—2017《测量不确定度评定和表示》相关要求,分析全部测定过程中测量不确定度的来源并对各不确定度分量进行定量评估。研究发现,测试不确定度主要由样品及标液稀释过程、测量重复性引入。在实际测试过程中可以通过严格控制标准曲线的制作过程、增加测量次数、提高定容容器定量精度、选择合适的移液器具措施有效地提高测试结果的准确度和可靠性。

Element mercury contained in automobile brake friction linings is quantitatively analyzed by cold atomic absorption mercury vapor meter.According to the relevant requirements of GB/T 27418—2017‘Guide to the evaluation and expression of uncertainty in measurement’,the sources of measurement uncertainty in the whole test process are analyzed,and each uncertainty component is quantitatively evaluated.It is found that the uncertainty is mainly caused by the dilution process of sample and standard solution and the repeatability of measurement.In the actual test process,the accuracy and reliability of the test results can be effectively improved by strictly controlling the production process of the standard curve,increasing the number of measurement,improving the quantitative accuracy of the constant volume container,selecting the appropriate pipette.