利用不确定度质控图进行实验室内部质量控制

Uncertainty control chart for laboratory internal quality control

测量不确定度是对测量结果质量的定量表征,GB/T 27025-2008明确要求实验室应给出结果的不确定度。采用GB 5009.5-2016《食品中蛋白质的测定》测定蛋白质含量,利用三天三平行实验确定方法的不确定度为:蛋白质质量分数的2.7%。在此基础上,分别利用不确定度和标准偏差建立质控图,发现二者的控制限相近,但不确定度质控图的控制限范围略小于标准偏差质控图。

Measurement uncertainty is the quantitative characterization of the result＇s quality.GB/T 27025-2008 clearly requires that the laboratory should ensure the uncertainty of results.The protein content was determined by GB 5009-2016,and the uncertainty of the method was determined by three parallel experiments.Finally,the uncertainty was 2.7% of protein concentration.On this basis,the control chart was made by uncertainty and standard deviation,respectively.The control limit of the two control charts were similar,but the limit range of uncertainty control chart was slightly less than that of the standard deviation.