分光光度计法测定饲料中总磷的不确定度评定

The Uncertainty Evaluation of Total Phosphorus of Feed by the Spectrophotometer Method

根据GB/T 6437—2002饲料中总磷的测定分光光度法中分光光度法测定饲料中总磷含量的测量不确定度进行评定。根据JJF1059—1999测量不确定度评定和表示的要求,分析了该测量过程的测量不确定度来源,建立数学模型,对测量不确定度的各个分量进行计算,最后合成求出标准不确定度和扩展不确定度。该法测定饲料中总磷含量为0.700 1%时,其扩展不确定度为0.006 6%。不确定度最主要的来源是标准溶液的制备和标准曲线的绘制。

According to GB/T 6437-2002 ＂Detection of total phosphorus in feed, spectrophotometer method＂, we evaluate the uncertainty in measurement of total phosphorus in feed by the spectrophotometer method. According to the standards of JJF 1059-1999 ＂Evaluation and Expression of Uncertainty in Measurement＂, we analysis the source of uncertainty in measurement during the process, build the mathematical model, count every component of uncertainty in measurement. At last, we obtain the standard uncertainty and the expanded uncertainty. When the total phosphorus of feed come to 0.700 1%, the expanded uncertainty is 0.006 6%. The main source of the uncertainty is the preparation of the standard solution and the drawing of the standard curve.