分光光度法测定空气中氨的不确定度评估

Evaluation of Uncertainty for Determination of Ammonia in Air by Spectrophotometry

氨气是一种被低估的有毒碱性气体,会对人体、环境、动物的健康造成长期影响。为提高纳氏试剂分光光度法测定环境空气和废气中氨的结果准确性,根据JJF1059.1—2012《测量不确定度评定与表示》及第1号修改单,分析了各种不确定度的来源,在规定的测量条件下,计算出测量不确定度。实验室对标准溶液纯度、量器、采样过程、曲线拟合及重复性进行不确定度评估,发现采样过程产生的不确定度和曲线拟合时产生的不确定度是影响测定结果的主要因素。

Ammonia is an undervalued toxic alkaline gas that has long-term effects on human,environmental and animal health.In order to improve the accuracy of the results of determination of ammonia in ambient air and waste gas by Nessler's reagent spectrophotometry,the sources of various uncertainties were analyzed according to JJF 1059.1-2012"E-valuation and Expression of Uncertainty in Measurement"and Amendment No.1,and the measurement uncertainties were calculated under the specified measurement conditions.The laboratory evaluated the uncertainty of standard solution puri-ty,measuring instrument,sampling process,curve fitting and repeatability,and found that the uncertainty generated in the sampling process and the uncertainty generated during curve fitting were the main factors affecting the results.