饮用水中铜绿假单胞菌检测结果的不确定度评定

目的:根据微生物学科特点,探讨适合于包装饮用水中铜绿假单胞菌检测结果的不确定度评定方法和如何利用扩展不确定度对限值附近的检测结果进行符合性判定。方法:按照GB 8538—2016的规定方法,对人工污染的包装饮用水样品进行铜绿假单胞菌检测,得到原始数据,进行统计学处理,建立数学模型,分析检测过程和数据处理过程中的不确定度来源,并使用A类和B类评定方法得到检测结果的不确定度和结果报告范围。结果:重复检测样品30次,合成不确定度u=0.037634,扩展不确定度U=0.077,检测结果T的报告范围为23~33 CFU/250 mL。结论:证实了不确定度评定在微生物实验中的必要性和可行性,建立了一种可参考的数学模型,并对出现在要求限值附近的检测结果利用扩展不确定度进行了符合性判定。

Evaluation of Uncertainty of Detection Results of Pseudomonas Aeruginosa in Drinking Water

Objective:According to the characteristics of microbiology,to discuss the uncertainty evaluation method suitable for the detection results of Pseudomonas aeruginosa in packaged drinking water and how to use the expanded uncertainty to determine the compliance of the detection results near the limit.Method:In accordance with the method specified in GB 8538—2016,the artificially contaminated packaged drinking water samples were tested for Pseudomonas aeruginosa,the original data was obtained,statistical processing was performed,mathematical models were established,and the errors in the testing process and data processing were analyzed The source of the certainty,and the uncertainty of the test results and the scope of the result report using the A and B evaluation methods.Results:The sample was repeated 30 times,the combined uncertainty u=0.037634,the expanded uncertainty U=0.077,and the report range of the test result T was 23~33 CFU/250 mL.Conclusion:The necessity and feasibility of uncertainty evaluation in microbiological experiments are confirmed,a mathematical model that can be used for reference is established,and uses extended uncertainty to determine compliance with the test results appearing near the required limit.