分光光度法测定化妆品中二氧化钛的不确定度评定

Evaluation of Uncertainty for Determination of Titanium Dioxide in Cosmetics by Spectrophotometric

目的:为更好服务化妆品安全监管,推动化妆品产业高质量发展,提升质量控制水平,优化科学监管模式,本次考察《化妆品安全技术规范》(2015年版)理化检验方法5.3二氧化钛的检验可靠性和准确性。方法:根据《化妆品安全技术规范》(2015年版)理化检验方法5.3二氧化钛,本文采用分光光度法测定化妆品中二氧化钛含量并对测量不确定度进行分析评定,建立分析测定防晒美白类化妆品中二氧化钛的不确定度数学模型,分析了影响不确定度的主要来源,并对各不确定度分量进行评定和合成,计算扩展不确定度。结果:钛含量为2.43%,在95%置信区间,扩展不确定度0.052%(k=2)。结论:通过系统分析,确定影响不确定度主要来源有:样品重复性、标准物质和加标回收,方法合理,结果精确,可运用到实际工作中,为系统评价检测结果的准确程度和方法的可靠性提供依据。

Objective:to serve the safety supervision of cosmetics better,promote the high-quality development of the cosmetics industry,improve the level of quality control,and optimize the scientific supervision model,we investigated the reliability and accuracy of titanium dioxide examination 5.3 in《technical standard for safety of cosmetics》(2015 edition).Methods:According to the method of physical and chemical examination 5.3 in《technical standard for safety of cosmetics》(2015 edition),a mathematical model was established,and the main sources of uncertainty were analyzed,the uncertainty components were evaluated and synthesized,and the extended uncertainty was calculated.Results:The content of titanium dioxide was 2.43%,and the expanded uncertainty was 0.052%(k=2)in the 95%confidence interval.Conclusion:through systematic analysis,the main sources of uncertainty were determined as follows:sample repeatability,preparation of standard substance and recovery of standard addition.It was proved that the evaluation method was reasonable,the results were accurate and effective,and can be applied to practical work,it provided a basis for evaluating the accuracy of detection results and the reliability of the method.