废水中硝基苯类化合物的测量不确定度评定

Uncertainty Evaluation for Determining Nitroaromatics in Wastewater

根据HJ 648-2013《水质硝基苯类化合物的测定液液萃取气相色谱法》的检测原理和方法,结合CNAS-GL06《化学分析中不确定度的评估指南》和JJF 1059-1999《测量不确定度评定与表示》的基本程序,以测定水中2,4-二硝基甲苯的含量为例,评定了气相色谱法测定水中硝基苯类化合物含量的不确定度,建立了数学模型,分析了各不确定度分量,将不确定度分量合成,并计算了其测定结果的扩展不确定度。结果表明:用气相色谱法测定水中硝基苯类化合物的含量,其不确定度主要来源为校准曲线拟合和测量重复性2个因素。

According to the basic principle and method given in HJ 648-2013 Water quality-Determination of nitroaromatics by gas chromatography, the components of uncertainty in the measuring process were studied and analyzed as the procedure for uncertainty assessment described in CNAS-GL06 Guidance on Evaluating the Uncertainty in Chemical Analysis and JJF1059-1999 Evaluation and Expression of Uncertainty in Measurement. And the combined uncertainty was calculated and evaluated using achieved results and related data. Taking 2,4-Dinitrotoluene for example, the results showed that the major factors of uncertainty in measurement were calibration curve fitting and measurement reproducibility.