火焰原子吸收分光光度法测定化妆品中铅含量的不确定度评估

目的评估火焰原子吸收分光光度法测定化妆品中铅的测量不确定度,使实验结果更具客观性和准确性。方法根据测量不确定度的评定理论,通过实际样品测定,分析和计算整个测定过程中不确定度的可能来源。结果采用火焰原子吸收分光光度法测定化妆品中铅含量时,不确定度主要来源于标准工作曲线的拟合及样品预处理溶液的浓度测定和回收率测定过程,而称样量、定容体积、标准溶液的配制、重复性测定等过程引入的误差对不确定度的影响则相对较小,在今后的评估过程中根据实际情况可以忽略。结论火焰原子吸收分光光度法测定化妆品中铅含量的扩展不确定度为7.06%。

Evaluation on the Uncertainty of Lead Analysis in Cosmetics by Flame Atomic Absorption Spectrometry

Objectives In order to have a more objective and accurate result, the uncertainty of lead content in cosmetics detected by Flame Atomic Absorption Spectrometry（FAAS） was evaluated. Methods Based on the theory of evaluating uncertainty, the sources of uncertainty in the whole testing process were analyzed and calculated. Results The main sources of uncertainty from detecting lead in samples were the combination of fitting the working curve, determining the concentration of solution for preprocessing samples and the determination of recoveries, while the influence from other factors was less, such as weighing and making constant volume of sample, the preparation of standard solution, and repeated measurement. Conclusion The expanded uncertainty of lead content in cosmetics determined by Flame Atomic Absorption Spectrometry （FAAS） was 7.06%.