滴定法测定饲料添加剂中硫酸亚铁含量的不确定度探讨

依据HG2935—2000饲料级一硫酸亚铁标准规定，对重铬酸钾滴定法测定硫酸亚铁含量的不确定进行了评定，建立了测量过程中各个分量的数学模型，并估算了各不确定度分量对总不确定度的影响。结果表明，在置信概率水平为95％时，硫酸亚铁含量测量结果报告为x=（80．34±0．48）％，k=2。该方法适用于硫酸亚铁含量的不确定评定，其中影响硫酸亚铁含量的不确定度主要来源是滴定体积所引入。

Assessment of Uncertainty of Ferrous Sulfate in Feed Additive by Titration

The uncertainty of Ferrous sulfate in feed additive was assessed according to the method of HG2935-2000- feed additive Ferrous sulfate. A mathematical model for each component was established and the uncertainty components were estimated. The results showed the report of uncertainty of FeSO4 in additive expressed as X=（80.34±0.48）%, k=2 at the confidence level of 95%. This method can be used to evaluate the uncertainty of Ferrous sulfate in feed additive by titration. The main factor that affected the uncertainty comes from the Uncertainty of titration volume.