中文摘要：

胭脂红是食品添加剂中最常用的一种食用色素之一,国家标准对其在食品中添加的剂量有明确的规定,研究其荧光光谱特性具有一定的实际意义。文章分别从理论与实验上对220-400 nm不同激发波长下胭脂红标准溶液的荧光光谱进行了分析,结果表明,胭脂红可以产生较强的荧光,分别在420,530,635,687 nm波长处产生了4个荧光峰,各荧光峰的最佳激发波长也不尽相同,文章给出了相应的荧光光谱图。经研究认为胭脂红荧光是由—OH中的n电子的n→π^＊跃迁和奈环中的π电子的π→π^＊跃迁这两类跃迁而产生的,其中420 nm处的荧光峰是由n→π^＊跃迁产生的,而530,635和687 nm这3个波长处的荧光峰是由π→π^＊跃迁而产生的,同时其4个波长处的荧光相对强度随激发波长的变化相对改变不同,文章分别从微观机理上给出了一定的解释。研究胭脂红的荧光光谱及其特性可为其他偶氮类色素的荧光光谱研究提供参考,同时能为食品安全检测提供新的方法与途径。

英文摘要：

The fluorescence spectra of ponceau 4R induced by 220-400 nm light were studied in the present paper.The result shows that ponceau 4R has four obvious fluorescence spectral peaks respectively located at 420,530,635 and 687 nm,each of these fluorescence spectral peaks has different best induced light,and the corresponding fluorescence spectra were listed.It was considered that this fluorescence comes from the transition n→π^＊ of n electrons in the —OH and π^＊→π of π electrons in the naphthalene.The fluorescence spectral peaks at 420 nm come from the transition n→π^＊ and the other three fluorescence spectral peaks come from π^＊→π.But the intensity of the four fluorescence spectral peaks changes differently with the excited wavelength.This paper attempted to give the expression of the four fluorescence spectral peaks based on the microcosmic mechanism.The reason for that ponceau 4R has complex fluorescence characteristic is that ponceau 4R not only has big and conjugate structure such as naphthalene and provides electron group —OH which can intensify its ability to emit fluorescence,but also absorbs electron group such as NN which can depress its ability to emit fluorescence.Investigation on the fluorescence spectra and its characteristics will contribute to the study on the fluorescence spectra of other azo pigment and help find a new way for checking food safety.