番茄红素可见吸收光谱和荧光光谱的测量与分析

The Measurement and Analysis of Visible-Absorption Spectrum and Fluorescence Spectrum of Lycopene

采用ICCD光谱探测系统对不同浓度番茄红素的二硫化碳溶液吸收谱的相对吸收强度进行了测量,结果显示在一定浓度范围内,番茄红素稀溶液的吸收规律满足朗伯-比尔定律;分别用丙酮、正己烷、石油醚、苯、乙酸乙酯和二硫化碳作为溶剂对番茄红素可见吸收光谱进行了测量,对结果进行分析后发现苯、乙酸乙酯和二硫化碳的番茄红素溶液的特征吸收峰的波长位置与以丙酮作为溶剂相比有不同程度的红移效应;番茄红素-丙酮溶液中加入水后溶液颜色随着加水量的增加逐渐变浅,溶液吸光度降低,当丙酮与水的体积比为4:1时吸收光谱在紫外出现一新的吸收峰.产生这些现象的原因是番茄红素溶于不同溶剂时,溶剂分子对番茄红素分子作用不同.用荧光光度计采集不同浓度的番茄红素丙酮溶液的荧光光谱,结果表明番茄红素溶液的荧光光谱主要集中在500～680 nm波段,浓度低于50μg·mL-1时,番茄红素的荧光强度随着浓度的增加而呈线性增加.当浓度高于60μg·mL-1时,荧光强度因为番茄红素分子间的相互作用而下降.

Using ICCD spectral detection system, the absorbency of lycopene-carbon bisulfide solution with different concentration was measured, and the result shows that in a specified range the absorption rule of lycopene solution agrees with Lambert-Beer Law. Absorption spectral wavelength shifts were measured respectively when lycopene was dissolved in acetone, normal hexane, petroleum ether, benzene, ethyl acetate, and carbon bisulfide, and comparing to acetone, different red-shift appeared when lycopene was dissolved in benzene, ethyl acetate, and carbon bisulfide when water was added in lycopene-acetone solution, the absorbency of lycopene droped, the fine structure of absorption spectrum became indistinct, and a new absorption peak appeared in UV. The reason for these phenomena is that the solvent molecule had different effect on lycopene molecule when lycopene was dissolved in different solvent. Using fluorecence spectrophotometer, fluorescence spectra of lycopene in different concentrations were collected, and the results show that the fluorescence spectra of lycopene were mairdy in 500-680 nm. When concentration was lower than 50 μg·mL^-1 , the fluorescence intensity linearly increased with increasing concentration, and when concentration was higher than 60μg·mL^-1, the fluorescence intensity dropped because of the interaction between lycopene molecules.