石墨炉原子吸收光谱法测定尿中铅不确定度评定

Uncertainty of determining lead in urine by graphite furnace atomic absorption spectrometry

目的研究石墨炉原子吸收光谱法测定尿中铅含量不确定度的评定,找出影响不确定度的因素。方法用石墨炉原子吸收光谱法测定尿中铅,根据CNAS-CL07《测量不确定度评定与表示》有关规定分析不确定度的来源。结果合成标准不确定度为0.013 9μmol/L,扩展不确定度为0.027 8μmol/L。结论石墨炉原子吸收光谱法测定尿中铅的过程中重复测定是该方法不确定度的主要来源。

Objective To evaluate the uncertainty of determining lead content in urine by graphite furnace atomic absorption spectrometry,and find out the influent factors of uncertainty. Methods Lead in urine was determined by graphite furnace atomic absorption spectrometry,according to CNAS- CL07 Evaluation and Expression of Uncertainty in Measurement,the relevant provisions of the sources of uncertainty were analyzed. Results The combined standard uncertainty was0. 013 9 μmol /L,the expanded uncertainty was 0. 027 8 μmol /L. Conclusion Repeated measurement is the main source of uncertainty in the process of determination of lead in urine by graphite furnace atomic absorption spectrometry.