虾青素油灰分测定的不确定度评定

Evaluation of uncertainty of determination of ash in astaxanthin oil

目的建立虾青素油灰分测定的不确定度的评定斱法。方法采用国标斱法GB5009.4-2016《食品中灰分的测定》第一法对虾青素油灰分进行测定,依据JJF1059.1-2012《测量不确定度评定与表示》对测定中的各分量分析量化,评定出被测量的标准不确定度和扩展不确定度,给出各分量对不确定度的贡献。结果通过计算,相对标准不确定度u_c(x)=0.019 g/100 g,扩展不确定度U=0.038 g/100 g。结论此次评定不确定度的主要来源为灰分质量m引入的,样品质量M引入的不确定度贡献很小。对重量法测样品灰分的不确定度评定时,其分量不确定度的贡献大小不是恒定的,不确定度贡献的大小应根据样品中灰分质量来判断。

Objective To establish an evaluation method for evaluation of uncertainty of determination of ash in astaxanthin oil.Methods The ash in astaxanthin oil was detected by GB5009.4-2016 Determination of ash in food method I.According to JJF 1059.1-2012 Evaluation and expression of measurement uncertainty,the quantitative analysis of each component in the measurement was carried out.The standard uncertainty and expanded uncertainty of the measurement were evaluated,and the contribution of each component to the uncertainty was given.Results Through calculation,the relative standard uncertainty was u_c(x)=0.019 g/100 g,and the extended uncertainty was U=0.038 g/100 g.Conclusion The main source of uncertainty in this evaluation is the introduction of ash mass m,and the uncertainty contribution of sample mass M is very small.When evaluating the uncertainty of gravimetric ashes measurement,the contribution of component uncertainty is not constant.The contribution of uncertainty should be judged according to the quality of ash in samples.