地下水中菌落总数测量不确定度的评定

Assessment of Uncertainty in the Total Number of Colonies in Groundwater

目的:对地下水中菌落总数的测量不确定度进行分析评定。方法:根据HJ 1000-2018《水质细菌总数的测定平皿计数法》对地下水中菌落总数进行平板计数法的检测,按照《JJF 1059.1-2012测量不确定度评定与表示》中A类不确定度和B类不确定度进行菌落总数的评定。结果:某环境园地下水的扩展不确定度为0.0312,在95%置信区间内,菌落总数报告值的范围为2.3×10^(2)~2.6×10^(2)CFU/mL。结论:重复性引入的不确定度对于样品结果的影响大于样品移取和样品稀释过程引入的不确定度,但进行菌落总数不确定度评定时,应该全方面考虑各过程引入的不确定度。

Objective:To analyze and evaluate the measurement uncertainty of the total number of colonies in groundwater.Methods:The total number of colonies in groundwater was detected by plate counting method according to Determination of total number of bacteria in water quality,plate count method(HJ 1000-2018),and the total number of colonies was evaluated according to the Type A and Type B uncertainties were evaluated by Evaluation and Expression of Uncertainties in Measurement(JJF 1059.1-2012).Results:The extended uncertainty of groundwater in an environmental park was 0.0312,and the reported value of total colonies ranged from 2.3×10^(2) to 2.6×10^(2) CFU/mL within the 95%confidence interval.Conclusion:The uncertainty of reproducible introduction has a greater influence on sample results than that of sample pipetting and sample dilution,but the uncertainty of total colony count should be evaluated in all aspects.