镉标准溶液配制结果的不确定度评定

Uncertainty Evaluation for the Results from the Preparation of Cadmium Standard Solution

选择氧化镉标准物质,配制成质量浓度为1000μg/mL的镉标准溶液,利用等离子体质谱法对标准溶液进行了定值与稳定性检验。通过对镉标准溶液配制过程不确定因素的描述,以95%概率下的扩展因子2获得标准溶液浓度配制标示值的扩展不确定度。实验数据表明,所配制的标准溶液稳定性可达2年。

Cadmium oxide is used as the raw material of the certified reference material and is prepared to cadmium standard solution with concentration of 1000 μg/mL. The homogeneity, stability and certified value of the solution are tested by inductively coupled plasma-mass spectrometry. The sources of uncertainty produced in analysis process were discussed and the uncertainty of Cd standard solution was assessed. The expanded uncertainty was obtained from combined standard uncertainty multiplied by expanded factor of 2 under the confidence level of 95% and the experimental data also shows that stable period of Cd standard solution is two years.