自适应MCM法和GUM法评价直接进样测汞法测定稻谷中总汞的不确定度比较研究
Comparative Analysis for Evaluation of Measurement Uncertainty of Direct Injection Mercury Determination in Rice by Adaptive MCM Method and GUM Method
季一顺 1胡斌 1张爱英 1王新文 1梅华1
作者信息
- 1. 安徽省粮油产品质量监督检测站,合肥 230031
- 折叠
摘要
重金属汞污染是危害粮食安全的重要问题,直接进样测汞法的检测过程中需要对检测结果做好质量控制.检测结果需要识别实验过程中各环节对结果的影响大小.基于GB/T 27404-2008《实验室质量控制规范食品理化检测》附录F中对实验室开展新项目所需验证的各种项目:回收率、标准曲线、测定低限、精密度、准确度等.使用自适应蒙特卡洛法(adaptive Monte Carlo method,MCM)和测量不确定度表示指南方法(Guide to the expression of uncertainty in measurement,GUM)分别对直接进样测汞法开展不确定度评定.GUM法得到的不确定范围为(0.019 3±0.001 7)mg/kg(k=2);MCM法得到的不确定度置信区间(95％)为[0.017 7,0.021 1];使用MCM Alchimia软件对2种方法的不确定度概率密度拟合曲线,MCM法与GUM法评价结果一致性较好.分析不确定度评定过程中各不确定度贡献率,回收率和标准曲线拟合过程引入不确定度在检出限处引入的不确定度分量较大,建议在方法验证和不确定度评定中使用定量限作为加标回收率和标准曲线最小浓度点.
Abstract
Mercury pollution has been a serious problem that endangers food safety.During direct injection mer-cury determination method,it is necessary to strengthen the quality control of the detection results and identify the impact of each procedure in the experimental process on the results.Based on Appendix F of GB/T 27404-2008 Criterion on Quality Control of Laboratories-Chemical Testing of Food,the test results of recovery rate,standard curve,lower limit of determination,precision,accuracy and other verification items required for a new project has been obtained.The adaptive Monte Carlo method(MCM)and the Guide to the expression of uncertainty in measure-ment(GUM)method were used to evaluate the uncertainty of the direct injection mercury determination method re-spectively.The testing result of the sample obtained by GUM method was(0.019 3±0.001 7)mg/kg(k=2);the confidence interval(95％)of the sample result obtained by MCM was[0.017 7,0.021 1].MCM Alchimia software was used to fit the uncertainty probability density curve of the two methods,the evaluation results of MCM and GUM method were in good agreement.The contribution rate of each uncertainty in the uncertainty evaluation process has been analyzed.At the detection limit,the proportion of uncertainty contributed by the recovery rate and standard curve fitting process was larger.As a consequence,it was recommended to use the quantitative limit as the minimum concen-tration point of the spiked recovery rate and standard curve in method verification and uncertainty evaluation processes.
关键词
稻谷/汞/不确定度/自适应蒙特卡洛法/GUM法Key words
paddy/mercury/uncertainty/adaptive Monte Carlo method/GUM method引用本文复制引用
基金项目
国家粮食和物资储备局行业标准制修订项目(2018)(国粮办发[2018]329号)
粮食质量安全监测项目(2022)(国粮发2022[58]号)
出版年
2024
NETL
NSTL
万方数据