分光光度法测定工作场所空气中氨含量的不确定度分析

Uncertainty analysis on determination of ammonia in air of the workplace by spectrophotometry

目的建立分光光度法测定工作场所空气中氨含量不确定度方式。方法依照JJF1059-1999《测量不确定度评定与表示》,建立数学模型,计算各不确定度分量和合成不确定度。结果标准溶液配制引入的标准不确定度分量为0.823%,由标准曲线求得样品溶液浓度引起的标准不确定度为0.062 8,样品取样与定容体积引起的标准不确定度为0.008 2,标准采样体积引入的标准不确定度为0.005 4,合成相对标准不确定度为0.06,扩展不确定度为0.38。结论该方法适用于分光光度法测定氨含量的不确定度评定。

[Objective]To establish the uncertainty assessment method for determination of ammonia in air of the workplace by spectrophotometry.[Methods]According to the Evaluation and expression of uncertainty in measurement（JJF 1059-1999）,the mathematic model was established to calculate the uncertainty components and synthesis uncertainty.[Results]The uncertainty component caused by standard solution preparation was 0.823%,the uncertainty caused by sample concentration which was calculated by standard curve was 0.062 8,the uncertainty caused by volume of sampling and dilution was 0.008 2,and the uncertainty caused by standard sampling volume was 0.005 4.The synthesis relative uncertainty was 0.06,and the expanded uncertainty was 0.38.[Conclusion]This method can be used for uncertainty evaluation in determination of ammonia by spectrophotometry.