容量法测定腐植酸肥料中可溶性腐植酸含量的不确定度评定

Evaluating Uncertainty in Determination of Soluble Humic Acid content in Humic Acid Fertilizer by Volumetric Method

采用容量法对腐植酸肥料中可溶性腐植酸含量测定过程进行了研究,通过不确定度的数学模型,确定了不确定度的来源,系统分析并计算了测定全过程的不确定度分量、合成了标准不确定度及扩展不确定度。结果表明:容量法测定腐植酸肥料中可溶性腐植酸含量为(36.62±0.71)%,K=2;按引入标准不确定度分量贡献大小排序,依次为测量重复性、测量体积,重铬酸钾标样、试验称量。此不确定度评定方法,适用于可溶性腐植酸含量分析,可作为腐植酸等级判定依据。

The determination of soluble humic acid content in humic acid fertilizer was studied by volumetric method,through the mathematical model of uncertainty, the source of uncertainty was determined. The uncertainty components of the whole process were analyzed and calculated, and the standard uncertainty and the extended uncertainty were synthesized. The results showed that the content of soluble humic acid in humic acid fertilizer was(36.62±0.71) %, K=2. According to the contribution of the introduced standard uncertainty component, the order was measurement repeatability, measurement volume, potassium dichromate standard sample and test weighing.This uncertainty assessment method was applicable to the analysis of soluble humic acid content and could be used as the basis for determining the grade of humic acid.