大肠菌群MPN计数法不确定度评估.pdf

第7卷第1期
食品安全质量检测学报
2016年1月
Journal of Food Safety and Quality
Jan.,2016
大肠菌群MPN计数法不确定度评估
姚丽芳,朱洪坤,李蔚,赵颐睛
上海出人境检验检疫局工业品与原材料测技术中心,上海200331)
摘要:目的为减少大肠菌群检测中的实验误差,提高檢验精确度,对大肠菌群MPN计数法不确定度进行
评估。方法使用大肠杆茵标准菌株,分析大肠茵群检测结果的不确定度来源,对测定过程中引入的不确定度
分量进行评定。采用合成的方法计算检验结果的不确定度。结果合成不确定度为0.06398,扩展不确定度为
0.1446(以对数计)。大肠杆菌含量范固结果为1212~-2358 MPN/ml。结论本研究发现重复性对不确定度影响
最大,应在分析过程中注意控制。
关键词:大肠菌群;不确定度评估;MPN法
Uncertainty evaluation ofcoliform bacteria MPN counting method
YAO Li-fang, ZHU Hong-hun, LI Wei, ZHAO Yi-qing
(Technical Center for Industrial Produc! and Raw Muterial Inspection and Testing of Shanghaientry-exit nspection and
Quarantine Bureaw, Shanghai 20D331, China
ABSTRACT Obiective To evaluate the uncertainty of coliform bacteria MPN counting method for reduce
experimcnt error and improve test precision. Methods The standard strains of Escherichia coli was used, and
the uncertainty sources of coliform bacteria were analyzed, then the uncertainty components introduced in the
experiment were evaluated. Synthetic method was used to calculate the uncertainty. Results The combined
uncertainty was 0.0639, and the expanded uncertainty was u(]o)=0.1446.Coliform content was 1212-2358
MPN/ML. Conclusion The results showed that the repeatability was the greatest influence on the uncertainty,
and it should be controlled in the test
KEY WORDS: coliform; uncertainty evaluation, MPN
言
每一项有数值要求的测量结果进行测量不确定度评
估,且GRT27025-2008《检测和校准实验室能力的
测量不确定度是表征合理地赋予被测量之值的通用要求》中明确规定:当不确定度与检测结果的
分散性,是与测量结果相联系的参数,在化学分析有效性或应用有关,或客户的指令中有要求,或当不
中应用较多,但在微生物檢验中应用并不多2。大肠确定影响到对规范限度的符合性时,检测报告中还
菌群作为粪便污染指标,是评价食品卫生状况的重需提供不确定度的信息。本研究按GB4789.3-2010
要指标之一N。CNAS-CL07:2041《测量不确定度评《食品微生物学检验大肠菌群计数》0第一法进行大
估和报告通用要求》の中规定检测实验室应有能力对肠菌群检测,评估检测结果不确定度,旨在为大肠菌
基金项目:上海出人境检验检疫局科技计划项目(HKO25-2014
Fund: Supported by Science and Technology Plan Prajecfof Shanghai Entry-exit Inspection and Quarantine Bureau( HK025-20
通讯作者:朱洪坤,高级工程师,主要研究领域为食品接触材料卫生检渢。E-rai!zhuk@scic.gov.cn
Industrial Products and Raw Materials, Shanghai 200331. China. E-mail: zhuhk. gov. n and Quarantine Bureau Ispection Center f
Corresponding author: ZHU Hong-kun, Senior Engineer, Shanghai Entry-exit Inspection
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