微生物法测定婴幼儿乳粉中维生素B12含量的不确定度评定

目的建立微生物法测定婴幼儿乳粉中维生素B₁₂含量的不确定评定方法。方法依据JJF1059.1—2012《测量不确定度评定与表示》及GB 5413.14—2010《食品安全国家标准婴幼儿食品和乳品中维生素B₁₂的测定》分析微生物法测定婴幼儿乳粉中维生素B₁₂含量过程中产生的各测量不确定度分量,计算测量结果的合成标准不确定度和扩展不确定度。结果当样品中维生素B₁₂含量为3.97μg/100 g时,其扩展不确定度为0.53μg/100 g(k=2)。结论标准溶液配制和标准曲线拟合计算待测溶液含量产生的不确定度对检测结果影响较大。

Uncertainty evaluation for determination of vitamin B12 in infant milk powder by microbiological method

Objective To establish an uncertain assessment method for the determination of vitamin B₁₂in infant milk powder by microbiological method.Methods According to JJF 1059.1—2012 Evaluation and representation of measurement uncertainty and GB 5413.14—2010 National food safety standard for the determination of vitamin B₁₂in infant food and dairy products,the components of measurement uncertainty generated during the determination of vitamin B₁₂in infant milk powder by microbial method were analyzed,and the synthetic standard uncertainty and extended uncertainty of the measured results were calculated.Results When the vitamin B₁₂content of the sample was 3.97 g/100 g,the expansion uncertainty was 0.53 g/100 g(k=2).Conclusion Theuncertaintiescaused by the preparation of standard solution and the calculation of standard curve fitting havea great influence on the test results.