冷原子吸收法测定水中汞的不确定度评定

Evaluation of Uncertainty on the Determination of Mercury in Water by Cold Atomic Absorption Spectrometry

目的根据JJF1059-1999《测量不确定度评定与表示》的要求,对水中汞测定结果的不确定度进行评定。方法考虑冷原子吸收测定法不确定度的主要来源包括仪器的精密度、标准物质引起的不确定度以及制备溶液过程中引起的不确定度,计算出各种不确定度分量并将其合成,以此计算出水中汞测定结果的不确定度。结果按数学模型计算水样中汞的浓度为0.0042mg/L,水样中汞测定结果的合成标准不确定度为0.0003mg/L,扩展不确定度为0.0006mg/L,结果表达为(0.0042±0.0006)mg/L。结论该方法适用于冷原子吸收法测定水中汞浓度的不确定度评定。

[ Objective] To evaluate the uncertainty of determination results of mercury in water by cold atomic absorption spectrometry, according to JJF 1059 - 1999 Evaluation and Expression of Uncertainty in Measurement. [ Methods ] Precision of the instrument, uncertainty caused by certified reference material and uncertainty caused by preparation solution were considered as the main sources of the uncertainty of cold atomic absorption spectrometry. The components of various uncertainties were calculated and synthesized, and the uncertainty of determination results of mercury in water was deduced. [ Results ] The concentration of mercury in water was 0.0042 mg/L according to the mathematical model. The combined standard uncertainty and expanded uncertainty of determination results were 0.0003 mg/L and 0.0006 mg/L respectively, and the uncertainty results was expressed as （ 0.0042 ± 0.0006 ） mg/L. [ Conclusion] This method is suitable for the evaluation of uncertainty on the determination of mercury in water by cold atomic absorption spectrometry.