石墨炉原子吸收光谱法测定化妆品乳液中铬含量的不确定度分析

目的分析石墨炉原子吸收光谱法测定化妆品乳液中铬含量的测量结果的不确定度，找出主要的影响因素。方法通过建立数学模型，对各个不确定度分量进行评估，得到合成不确定度和扩展不确定度。结果化妆品乳液中铬含量的测量结果为ω=（0．673±0．087）mg／kg（k=2，置信水平为95％）。结论影响测量结果不确定度的因素主要是样品的称重、消化和定容过程；标准溶液的纯度和稀释过程；原子吸收标准方法；结果的重复测定。

Analysis of uncertainty of the content of chromium in cosmetics and lotions by the measurement of graphite furnace atomic absorption spec- trometry

Objective To analyze the uncertainty of the measured results of the content of chromium in cosmetics and lotions via graphite furnace atomic absorption spectrometry,and to find out the main influence factors. Methods Mathematic model was established to assess each component of uncertainty,and composite uncertainty and expanded uncertainty were obtained. Results The measured result of the content of chromium in cosmetics and lotions was ω=（0.673±0.087）mg/kg （k=2,confidence level was 95%）. Conclusion The main factors affecting the uncertainty of the measured results are weighing,digestion and constant volume process of the sample;purity and dilution of the standard solution; standard method of atom absorption;repeated measurement of results.