紫外吸收和荧光光谱检测红茶中的胭脂红色素

Detection of Black Tea with Carminum Based on UV Absorption and Fluorescence Spectroscopy

提出并建立一种基于紫外-荧光相关谱掺胭脂红色素红茶的判别方法,并对掺入的胭脂红色素浓度进行定量分析。配置29个掺胭脂红茶汤(质量浓度范围0.1～20μg/m L)样品,室温下分别采集紫外可见吸收光谱和荧光光谱。在研究未掺入和掺入色素茶汤一维光谱特性的基础上,以胭脂红浓度为外扰,构建了同谱和异谱紫外可见-荧光相关谱,确认茶汤中胭脂红的紫外可见吸收峰和荧光特征峰位置。利用510 nm处吸收峰强度和433 nm处荧光峰强度对胭脂红进行定量分析,其相关系数均在0.99以上。

A discrimination method of black tea adulterated with carminum was proposed,and quantitative analysis of the carmine concentration was also carried out in black tea.Total 29 black tea samples adulterated with carminum(concentration range 0.1-20μg/mL)were prepared.The UV Vis absorption spectra and fluorescence spectra were collected at room temperature.On the basis of the study of the one-dimensional spectral characteristics of pure and adulterated black tea,the two-dimensional UV Vis and fluorescence correlation spectra were constructed with the concentration of carmine as the external disturbance,and the location of the UV absorption peaks and the fluorescence characteristic peak of carminum in the tea soup were confirmed.The absorption peak intensity at 510 nm and the intensity of fluorescence peak at 433 nm were used for quantitative analysis of carmine,with a correlation coefficient of more than 0.99.