直接干燥法测定高粱中水分的不确定度评定

Evaluation of Uncertainty in Determination of Moisture in Sorghum by Direct Drying Method

采用GB 5009.3—2016《食品安全国家标准食品中水分的测定》中的直接干燥法测定高粱水分含量,建立相应的数学模型,分析了测量不确定度的来源,并对测定结果的不确定度分量、合成不确定度和扩展不确定度进行计算和评定。结果表明,在实验条件中所测定高粱水分含量为13.5 g/100 g时,扩展不确定度为0.2 g/100 g(k=2)。影响合成不确定度的最主要因素为重复性试验和恒重过程,在检测过程中对试样进行充分混匀和严格执行恒重标准,可提高检测结果的准确性和稳定性。

The direct drying method in GB 5009.3—2016"National Food Safety Standard Determination of Moisture in Food"was used to determine the moisture content in sorghum,the corresponding mathematical model was established,the source of measurement uncertainty was analyzed,and the uncertainty components,synthetic uncertainty and expanded uncertainty of the measurement results were calculated and evaluated.The results showed that when the moisture content of sorghum determined in this experiment is 13.5 g/100 g,the expanded uncertainty is 0.2 g/100 g(k=2),and the uncertainty that affects the synthetic uncertainty was mainly caused by the repeatability test and constant weight process.Therefore,it is concluded that the accuracy and stability of the test results can be improved by fully mixing and strictly implementing the constant weight standard in the test process.