Evaluation of Uncertainty in the Plate Counting Method for Staphylococcus Aureus
Objective:Evaluating the measurement uncertainty of the plate counting method in GB 4789.10-2016,Food microbiological examination—Testing of Staphylococcus aureus,for milk powder matrix.Methods:An evaluation protocol is designed based on the revised version of RB/T 151,Guidelines for the estimation of measurement uncertainty of food microbiological quantitative detection.The technical uncertainty,matrix uncertainty,and distribution uncertainty are evaluated respectively,and the combined uncertainty and expanded uncertainty are calculated.Finally,the technical uncertainty or all of the uncertainty components can be selected,according to laboratory requirements.Results:The statistical analysis of the test results shows that the technical uncertainty is 0.0733 log10CFU/g,and the matrix uncertainty is 0.0518 log10CFU/g.For the distribution uncertainty,the poisson uncertainty and confirmation uncertainty need to be consider,which can be obtained by looking up tables in RB/T 151,or calculated by using the formulas listed is RB/T 151 based on each single test result.Conclusion:Following the revised version of RB/T 151 for uncertainty estimation,the approach is clear,the protocol design is concise,and the execution is smooth,which is very conducive to the uncertainty estimation of microbial examination methods in the laboratory.
万方数据
维普
