摘要
Abstract
In order to improve the detection ability of the total number of bacteria colonies in the laboratory and ensure the accuracy and reliability of the test results,the laboratory took part in the proficiency testing of the total number of bacteria colonies organized by IDEXX,and the quality control of the entire experiment was carried out from the five aspects of"personnel,equipment,materials,methods,and environment".The proficiency test blind samples were tested according to the requirements of Standard Examination Methods for Drinking Water-Part 12:Microbiological Parameters(GB/T 5750.12-2023)Section 4.1(Plate Counting Method)and Section 4.2(enzyme substrate method),and the results were satisfactory.The measurement uncertainty of detecting the total number of bacteria colonies in drinking water by plate counting method and enzyme substrate method was evaluated,and the sources of uncertainty were analyzed through repeatability testing,graduated pipette sampling and data rounding.On condition that the coverage pobability was 95%,and the coverage factor was 2.26,the expanded uncertainties of total number of bacteria colonies in proficiency test blind samples respectively were 0.099 9 and 0.026 2(log scale)for the plate counting method and enzyme substrate method.After taking the anti-logarithm,the total number of bacteria colonies in proficiency test blind samples by plate counting method and enzyme substrate method respectively were 121-192 CFU/mL,and 167-188 MPN/mL.关键词
菌落总数/能力验证/质量控制/不确定度/平皿计数法/酶底物法Key words
total number of bacteria colonies/proficiency testing/quality control/uncertainty/plate counting method/enzyme substrate method
