胶束增敏荧光法测定面膜中的荧光增白剂

Determination of fluorescent whitening agent in mask by micellar enhanced fluorescence spectrometry

建立简单、灵敏、快速的胶束增敏荧光法,对面膜中的荧光增白剂VBL进行定量检测.对检测条件进行选择,确定了最佳的检测条件:Ex=345nm、Em=430nm、Slit=5nm,5nm;根据荧光增白剂的光学性质、结合表面活性剂胶束增敏原理,对影响体系荧光强度的因素(增敏试剂种类、增敏剂浓度、温度等)进行了考察,确定的最佳增敏试剂为9.20×10-4 mol/L的CTAB(即为临界胶束浓度),最佳实验条件为34℃;利用单因素分析结合正交设计对样品预处理条件(提取剂的种类、浓度、料液比,提取时间、温度等)进行了筛选,确定了荧光增白剂的最佳提取工艺:提取溶剂为体积分数90%乙醇,料液比1∶75(g∶mL),提取时间30min,提取温度34℃.在最佳实验条件下,VBL+CTAB体系,在5.00×10-7~1.20×10-4 g/L内线性关系良好(r=0.995 8),检出限为1.91×10-7 g/L,平均回收率为101.64%~120.60%,相对标准偏差为1.41%~8.92%.本方法检测灵敏、重现性好、结果准确可靠,可用于面膜中荧光增白剂的定量检测,为中国相关监管机构对市场面膜的质量监测提供科学依据,对维护消费者身体健康有重要意义.

A simple,fast and sensitive analytical method was established for the determination of fluorescent whitening agent VBL in mask by micelle-sensitized fluorescence spectrometry.The detecting conditions were optimized.The wavelength of the excited and the emitted spectrum of VBL were 345 nm and430 nm,respectively.The slit widths were 5 nm,5 nm.According to the spectroscopic properties of VBL and the sensitization principle of surfactant micelle,the factors that influence the fluorescence intensity of the system（such as the type of sensitizer,the concentration of sensitizer and the temperature）were investigated.According to the various factors,the optimal experimental conditions were that the sensitizer was CTAB,the concentration of CTAB was 9.20×10^-4 mol/L（critical micelle concentrations,CMC）and the temperature was 34 ℃.Through single-factor and orthogonal experiments,the sample pretreatment methods for the VBL of the facial masks were optimized.The extraction solvent was 90%ethanol,the solid-liquid ratio was 1∶75（g∶mL）,the extracting time was 30 min,and the extracting temperature was 34 ℃.The result showed that the fluorescence enhancement value of the CTAB was linearly proportional to the concentration of VBL in the range of 5.00×10^-7～1.20×10^-4 g/L.The limit of detection was found to be1.91×10^-7 g/L,the average recovery was 101.64%～120.60%,and the standard deviation was 1.41%～8.92%.This method is sensitive,reproducible and accurate,and suitable for quantitative detection of VBL in facial mask.The method can provide the scientific basis for the quality monitoring of the market mask in China＇s relevant regulatory agencies,and is of great significance to the maintenance of consumer health.