分析合成食品色素的分子结构特点， 根据荧光与分子结构的关系， 理论上推断合成食品色素是荧光物质。 应用SP-2558多功能光谱测量系统， 测得胭脂红、 苋菜红、 柠檬黄、 日落黄、 亮蓝等五种最常用的合成食品色素标准溶液的三维荧光光谱。 结果表明， 胭脂红在波长330～430 nm的光激发下， 产生较强荧光， 荧光峰值波长为621 nm， 最佳激发波长为376 nm； 苋菜红在波长300～440 nm的光激发下， 产生较强荧光， 荧光峰值波长为643 nm， 最佳激发波长为370 nm； 柠檬黄在波长280～380 nm的光激发下， 产生很强荧光， 荧光峰值波长为565 nm， 最佳激发波长为315 nm； 日落黄在波长310～410 nm的光激发下， 产生较强荧光， 荧光峰值波长为592 nm， 最佳激发波长为348 nm； 亮蓝在波长320～390 nm的光激发下， 产生较强荧光， 荧光峰值波长为456 nm， 最佳激发波长为350 nm。 进而对这五种合成食品色素的荧光光谱进行了分析讨论。 结果可为食品色素检测和食品安全提供帮助。

According to the characteristic of synthetic food colors molecule and the relationship between fluorescence and molecular structure, and through analyzing, it has been concluded that synthetic food colors is fluorescent material. By using SP-2558 multifunctional spectral measuring system, the three-dimensional fluorescence spectra of ponceau 4R, amaranth, tartrazine, sunset yellow and brilliant blue were measured. The results show that ponceau 4R excited by light at the wavelength of 330-430 nm can generate a strong fluorescence at the 621 nm peak wavelength with its best excitation wavelength being 376 nm, amaranth excited by light at the wavelength of 300-440 nm can generate a strong fluorescence at the 643 nm peak wavelength with its best excitation wavelength being 370 nm, tartrazine excited by light at the wavelength of 280-380 nm can generate a strong fluorescence at the 565 nm peak wavelength with its best excitation wavelength being 315 nm, sunset yellow excited by light with wavelength of 310-410 nm can generate a strong fluorescence at the 592 nm peak wavelength with its best excitation wavelength being 348 nm, and brilliant blue excited by light at the wavelength of 320-390 nm can generate a strong fluorescence at the 456 nm peak wavelength with its best excitation wavelength being 350 nm. Moreover, the fluorescence spectra of the five kinds of synthetic food colors were discussed. These results can provide helps for testing of food colors and food safety.