维生素C荧光光谱的机理研究

以V_C标品为研究对象,利用荧光分光光度计分别采集了280³50 nm激发波长下的荧光发射光谱,结果表明:V_C溶液的最大荧光峰位于EX310 nm/EM400 nm,VC光谱的二阶导数有4个极值点和3个拐点,分别为:328、345、355、372、395、425、525 nm。通过理论分析,证实395 nm是-OH发生的n→σ*电子跃迁,二烯醇结构π→π*电子跃迁产生的荧光峰由于共轭体系的作用发生红移而位于425、525 nm。分子中的各个荧光团相互叠加且彼此制约,在分子团簇作用和水分子的H键的共同作用下,最终使得V_C溶液在400 nm有最大荧光峰。 

Study on fluorescence spectra mechanism of vitamin C

Taken standard vitamin C for research objects,fluorescence emission spectra were measured with fluorescence spectrophotometer and the excitation wavelength were 280 ~ 350 nm. The results showed that the fluorescence excitation and emission wavelengths of the vitamin C solution were 310 nm and 400 nm. The second order derivation of fluorescence spectrum had four extreme points and three inflection points which were 328,345,355,372,395,425,525 nm.Based on the theory analysis,we come to the conclusion that the fluorescence peak at395 nm was formed by- OH n→σ*- electron jumps.The dienes alcohols structure emitted a π→π*- electron jumps of maximum peak that were a little red shift at 425 nm and 525 nm.The reason was strong affected by conjugated system.Each of molecule fluorescent group were restricted and superimposed.The molecular clusters and H bond of water molecule made maximum fluorescence peak of vitamin C solution at 400 nm.