制何首乌配方颗粒需氧菌总数测定的不确定度评定

Evaluation of uncertainty in determination of total aerobic bacteria in formula granules of Radix Polygoni Multiflori Preparata

目的:对制何首乌配方颗粒中需氧菌总数测定的不确定度进行评定。方法:采用《中国药典》2020年版四部非无菌产品微生物限度检查法测定制何首乌配方颗粒中的需氧菌总数,通过建立数学模型,识别不确定度来源,对不确定度来源进行分析,量化每一个分量,合成测定结果的相对标准不确定度及扩展不确定度。结果:扩展不确定度为U=0.0826 log10(cfu/g),结果对数值取值区间为(2.4426±0.0826)log10(cfu/g),取反对数取值区间则为(230,340)cfu/g,k=2。结论:电子天平引入的不确定度贡献较小,供试液制备和稀释液加样、重复性实验引入的不确定度贡献较大。

Objective:Objective:Evaluating the uncertainty of the determination of aerobic bacteria in the formula granules of Radix Polygoni Multiflori Preparata.Methods:The total number of aerobic bacteria in Radix Polygoni Multiflori Preparata formula granules was determined by using the four non-sterile product microbial limit inspection method of the Chinese Pharmacopoeia 2020 edition.Through establishment of the mathematical model,identifying and analyzing the sources of uncertainty,quantifying each componens,and synthesizing the relative standard uncertainty and expanded uncertainty of measurement results.Results:The expanded uncertainty is U=0.0826 log10(cfu/g),the interval of numerical value is(2.4426±0.0826)log10(cfu/g),and the interval of negative number is(230,340)cfu/g,k=2.Conclusion:The contribution of uncertainty introduced by electronic balance is small,The uncertainty caused by the preparation of test solution,diluent sample addition and repeatability experiment contributed a lot.