气相分子吸收光谱法测定水中氨氮浓度不确定度评定

摘要

为了探究水中氨氮的不确定度来源，明确影响不确定度的各分量以及对该分量进行分析计算，如实反映测量的准确度，本文采用气相分子吸收光谱法进行研究。结果表明，当水体样品中氨氮浓度值到达1.45mg/L 时，考虑到测定结果会受到实验过程中标准溶液配制、曲线拟和程度以及仪器测量重复性等因素的影响，测量计算氨氮的相对合成标准不确定度为0.04mg/L，其中，最主要的分量来源是回归直线拟合程度。%For explore the sources of uncertainty of the determination of concentration of Ammonia nitrogen in the water sample, and reflect the measuring accuracy truthfully, gas phase absorption spectrometry is used to study in this paper. The results show that,when the Ammonia nitrogen concentration is 1.45mg/L in the water sample, consider the factors affect the measurement results such as detemr ination of the process of the preparation of the standard solution, curve fitting, and instrument measurement repeatability, measure and calculate the reelative synthetic standard uncertainty of ammonia nitrogen in water is 0.04mg/L,in which the main source of components is the degree of curve fitting.