口红的荧光和拉曼光谱特性的研究

人们消费方式的变化促使电商崛起，美妆市场呈爆发式增长，口红产品的安全成为关注焦点。面对品牌口红真伪问题，市场检测化妆品方法单一，对品牌口红的特征无针对性。采用三维荧光技术和共聚焦拉曼技术对某品牌真假口红的光谱性质进行了研究。三维荧光光谱显示五组口红均存在激发光峰值波长为320 nm左右，发射峰波长在372 nm附近的荧光（Ⅰ区）。A1，A2，A3，B1，B2和B3这6个样品中，激发光峰值波长为230 nm时会发出中心波长在400 nm左右的荧光，而在A4，A5，B4和B5这4个样品中，激发光峰值波长红移到250 nm左右，其荧光发射峰也发生了相应的红移，到450~470 nm（Ⅱ区）。此外，A5还存在激发光峰值波长550 nm，发射峰在590 nm附近的荧光；B1还存在270 nm激发，292 nm左右发射的荧光峰（Ⅲ区）。采用荧光强度相对法来定量分析，若都以Ⅰ区的荧光强度为1，口红不同色号间、同色号真假口红间的Ⅱ区和Ⅲ区的相对荧光强度显著不同。拉曼光谱显示正品口红中存在TiO₂的振动峰，也还存在大量的C-C，C-N，-CH₂和-NH₂等有机化官能团的振动特征峰。相比于正品口红，部分假口红中还存在四个特异性的振动峰，分别是228，447，609和1 090 cm-1，这与Fe₂O₃的拉曼峰位吻合。实验结果表明口红不同色号间、同色号真假口红之间均存在着明显的光谱差异，利用口红光谱的指纹特性可实现对真假口红的鉴别。

Study on Fluorescence and Raman Spectral Characteristics of Lipstick

With the rise of e-commerce and the explosive growth of the beauty makeup market, lipstick products’ safety become the focus of attention. In the face of the authenticity of brand lipsticks, the market detection method of cosmetics is single, and the characteristics of brand lipsticks are not targeted. In this paper, the spectral properties of a brand of true and false lipstick were studied using three-dimensional fluorescence technique and confocal Raman technique. According to the 3d fluorescence spectrum, the optimal excitation wavelength of all the five groups of lipsticks is about 320 nm, and the emission peak wavelength is about 372 nm (region Ⅰ). Among the six samples, A1, A2, A3, B1, B2 and B3, fluorescence with a central wavelength of about 400 nm will be emitted when the optimal excitation light wavelength is 230 nm. In A4, A5, B4 and B5 samples, the optimal excitation wavelength was redshifted to about 250 nm, and the fluorescence emission peak was redshifted to 450~470 nm (region Ⅱ). In addition, the optimal excitation wavelength of A5 is 550 nm, and the emission peak is near 590 nm. B1 also has a fluorescence peak excited at 270 nm and emitted around 292 nm (region Ⅲ). The relative fluorescence intensity method was used for quantitative analysis. If the fluorescence intensity of zone I was 1, the relative fluorescence intensity of zone Ⅱ and zone Ⅲ in different colors and between true and false lipsticks with the same color number were significantly different. Raman spectrum shows that there are vibration peaks of TiO₂ in authentic lipstick and a large number of vibration characteristic peaks of organic functional groups such as C-C, C-N, -CH₂ and -NH₂. Compared with the real lipsticks, there are four specific vibration peaks in some fake lipsticks, namely 228, 447, 609 and 1 090 cm-1, which is consistent with the Raman peak of Fe₂O₃. The experimental results show obvious spectral differences between different lipstick colors and between true and false lipsticks of the same color.