摘要
本研究建立了食品中大肠菌群、大肠埃希氏菌测量不确定度的评定方法,为其他食品微生物检测过程中的不确定度评定提供方法案例。依据GB 4789.3-2016《食品安全国家标准食品微生物学检验大肠菌群计数》、GB 4789.38-2012《食品安全国家标准食品微生物学检验大肠埃希氏菌计数》中第二法和JJF 1059.1-2012《测量不确定度评定与表示》,以已知添加菌株的能力验证样品为例,分析样品制备、稀释过程、加样过程及重复性检测引入的不确定度,构建数学模型评定不确定度。结果表明,样品中大肠菌群的扩展不确定度Uc=0.115,大肠埃希氏菌的扩展不确定度UE.coli=0.115(取置信概率p=95%,包含因子k=2.26)。检测过程中的不确定度来源由样品单次测量过程和重复测量过程中引入的不确定度组成,重复测量试验引入的不确定度贡献最大,占比均为97%。
This study is intended to establish a method for evaluating the uncertainty of coliforms and E.coli in food,and provide a uncertainty measurement approach case for the other food microbiological examination.According to the second method based on GB 4789.3-2016 National Food Safety Standard Food Microbiological Examination:Enumeration of Coliforms and GB 4789.38-2012 National Food Safety Standard Food Microbiological Examination:Escherichia coli Count and JJF 1059.1-2012 Evaluation and Representation of Uncertainty Measurement,this study took the added stains as known proficiency testing sample,analyzed the uncertainty introduced by sample preparation,dilution process,sample adding process and repeated measurement process.A mathematical model was established to analyze the uncertainty.The result shows that the coliforms expanded uncertainty(Uc)for the sample was 0.115(p=95%,k=2.26)and the E.coli expanded uncertainty(UE.coli)was 0.115 too.The uncertainty in the process was mainly composed of the uncertainty introduced by sample single test process and the uncertainty of repeated measurement process.The uncertainty of repeating measurement process was the most contribution to the uncertainty,both of which were 97%.
作者
游元丁
赵阳
徐孟怀
冉茂乾
李跃红
朱明
焦彦朝
李勤刚
YOU Yuan-Ding;ZHAO Yang;XU Meng-Huai;RAN Mao-Qian;LI Yue-Hong;ZHU Ming;JIAO Yan-Chao;LI Qin-Gang(Liupanshui Port Service Center,Liupanshui 553001;Comprehensive Technology Center of Guiyang Customs,Guiyang 550001;Liupanshui Customs House,Liupanshui 553001)
出处
《中国口岸科学技术》
2022年第7期84-91,共8页
China Port Science and Technology
基金
海关总署科研项目(2021HK207)。
