生活饮用水中总大肠菌群MPN法的不确定度评定  

Evaluation of uncertainty measurement of total coliforms in drinking water by MPN counting method

作　　者：张炜煜[1] 王岙[1] 杨修军[1] 刘桂华[1] 李青[1] 张立夫[1] ZHANG Wei-yu;WANG Ao;YANG Xiu-jun;LIU Gui-hua;LI Qing;ZHANG Li-fu(Jilin Center for Disease Control and Prevention,Changchun,Jilin 130062,China)

机构地区：[1]吉林省疾病预防控制中心

出　　处：《中国卫生检验杂志》2019年第21期2600-2603,共4页Chinese Journal of Health Laboratory Technology

摘　　要：目的探讨生活饮用水中总大肠菌群定量检测MPN法结果不确定度及评定方法。方法依据CNAS-CL07:2011《测量不确定度评估和报告通用要求》和GB/T 5750.12-2006《生活饮用水标准检测方法微生物指标》中总大肠菌群定量检测MPN法,以实例来评定MPN法测定结果的不确定度。结果采用多管发酵法检测样本中总大肠菌群含量为4.6×10^2 MPN/100 ml^1.6×10^4 MPN/100ml。合成标准不确定度为0.342。扩展不确定度为0.772。结论通过建立生活饮用水总大肠菌群定量检测的数字模型,对总大肠菌群定量检测(MPN法)进行不确定度评定,A类测量不确定度评定中重复性测量产生的不确定度分量最大,在检测过程中应注意控制;B类测量不确定度评定中刻度吸管和移液器进行取样过程所产生的不确定度相对较大,实验室环境温度、湿度变化对不确定度评定影响较小。Objective To investigate the uncertainty budget evaluation of MPN method for total coliforms in drinking water.Methods On the basis of the quantitative detection method of total coliforms MPN in CNAS-CL07:2011 Requirements for Measurement uncertainty and GB/T 5750.12-2006 Standard Examination Methods for Drinking Water-Microbiological Parameters,uncertainty evaluation with examples MPN determination results.Results The total coliform content in the samples by MPN was within 4.6×10^2 MPN/100 ml-1.6×10^4 MPN/100 ml.The combined standard uncertainty was 0.342,The expanded uncertainty was 0.772.Conclusion By establishing a mathematical model for quantitative detection of total coliform bacteria in drinking water,the measurement uncertainty of total coliform bacteria by MPN method was evaluated.The component of repetitive measurement is the largest in type A evaluation,and attention should be paid on the control in the detection process.In type B evaluation,the uncertainty caused by the sampling process of pipetteis is relatively large,the change of temperature and humidity in laboratory environment has little influence.

关 键 词：MPN 总大肠菌群 A类评定 B类评定 合成不确定度 扩展不确定度 

分 类 号：R123.1[医药卫生—环境卫生学]