凯氏定氮法测定大米中蛋白质的不确定度分析

UNCERTAINTY ANALYSIS ON DETERMINATION OF PROTEIN IN RICE BY KJELDAHL METHOD

采用GB/T5009.5-2003第一法,凯氏定氮法测定大米中蛋白质的含量,其测量不确定度来源于样品称量、消化、定容、移取消化液、蒸馏及滴定等过程。通过对各个不确定度分量的计算合成,找出影响测量不确定度的因素,并对各个不确定度分量进行评估,最终分析出样品大米中蛋白质的标准不确定度及扩展不确定度并描述了影响大米蛋白质测定结果各分量对其不确定度的相对贡献。

Protein content in rice was determined by Kjeldahl method,the first method of GB/T5009.5-2003,the measurement uncertainty was tracked from such experimental processes as sample weighing,digestion,volume,pipet digestion,distillation and titration etc..By calculation and synthesis of each component uncertainty,it figured out the factors affected the measurement uncertainty,and evaluated the uncertainty of each component,analyzed the standard uncertainty and expanded uncertainty of protein in rice samples,and described the relative contributions which affected various components results of rice protein on its uncertainty.