论文部分内容阅读
[目的]评定原子吸收光谱法测定玉米粉中铜、锌含量的测量不确定度。[方法]结合检验实际工作,对原子吸收光谱法测定玉米粉中铜、锌含量的测量不确定度进行评价,建立数学模型,分析该试验过程中测量不确定度来源,对样品检测过程中的样品称量、标准物质溶液转移、稀释定容、曲线拟合以及仪器测量重复性等影响不确定度的分量进行了分析。[结果]试验得出,在合成标准不确定度的各个分量中,标准曲线拟合和重复性试验引入的不确定度是对其影响最大的2个分量,必须严格控制好标准曲线校准和样品的重复测定过程。最终计算出玉米粉中铜、锌含量的扩展不确定度分别为(1.38±0.08)mg/kg、(10.20±1.20)mg/kg,取包含因子k=2。[结论]研究可为系统分析检测结果的准确程度和方法的可靠性研究提供参考。
[Objective] The research aimed to evaluate the uncertainty of measurement of copper and zinc in corn flour by atomic absorption spectrometry. [Method] Combined with the actual work of inspection, the measurement uncertainty of the determination of copper and zinc in corn flour by atomic absorption spectrometry was evaluated, the mathematical model was established, the sources of measurement uncertainty in the test were analyzed, Sample weighing, standard material solution transfer, dilute volume, curve fitting and instrument measurement repeatability and other components of the impact of uncertainty are analyzed. [Results] The results showed that the uncertainty introduced by the standard curve fitting and repeatability test is the two components which have the most influence on the components of the synthetic standard uncertainty. The standard curve calibration and the sample Repeated determination of the process. Finally, the extended uncertainty of copper and zinc content in corn flour was calculated as (1.38 ± 0.08) mg / kg and (10.20 ± 1.20) mg / kg, respectively. [Conclusion] The research can provide a reference for the systematic analysis of the accuracy of the test results and the reliability of the method.