连续流动在线UV消解测定海水中的总氮的不确定度评定

Uncertainty Evaluation in Determination of Total Nitrogen in Seawater by UV Digestion and Flow Injection Spectrophotome

采用连续流动在线UV消解测定海水中的总氮。对测量结果的不确定度进行了评定。分析了测量程序中不确定度的各项来源,包括样品采集、标准溶液制备、校准曲线回归、在线UV消解、样品回收率等分量引入的不确定度及其计算方法,最后合成标准不确定度,通过乘以95%概率下的扩展因子2,获得测量结果的扩展不确定度。

Total nitrogen in marine aquaculture wastewater were determined by UV digestion and flow injection spectrophotometry. The sources of uncertainty produced in analysis process were discussed and the volume of sample collection preparation of standard solution, standard curve regres- sion, dilution of sample, sample recovery of the UV digestion process, etc. were considered as the main sources of the measurement uncertainty . And the expanded uncertainty was obtained from syn- thetical standard uncertainty multiplied by expanded factor of 2 under the confidence level of 95%.