三种食用色素的电化学行为的理论计算与验证

THEORATICAL CALCULATION OF SOME PARAMETERS OF 3 KINDS OF EDIBLE PIGMENTS RELATING TO THEIR ELECTROCHEMICAL BEHAVIORS AND THEIR EXPERIMENTAL VARIFICATION

摘要: 用量子理论计算柠檬黄、日落黄、胭脂红的相对焓(Hm)、相对熵(Sm),计算柠檬黄、日落黄、胭脂红的还原电位分别为-0.969,-0.901,-0.854 V(vs.Ag/AgCl/Cl).探讨了琼脂对色素的电催化机理,采用循环伏安法在玻碳琼脂电极上研究了食用色素柠檬黄、日落黄、胭脂红的电化学行为,分别于-1.064,-0.910,-0.882 V(vs.Ag/AgCl/Cl)产生还原峰,理论预测与试验结果基本一致.

Abstract: Enthalpy (Hm) and entropy (Sm) of 3 edible pigments,tartrazine,sunset yellow and ponceau 4R,were calculated theoratically by quantum theory with their reductive potentials appeared at -0.969,0.901 and -0.854 V (vs.Ag/AgCl/Cl) respectively.The mechanism of electrocatalysis of agar toward the pigments was discussed.Electrochemical behaviors of the 3 pigments at the glassy carbon-agar electrode were studied by cyclic voltammetry,and their reduction peaks were observed at -1.064,0.910 and -0.882 V (vs.Ag/AgCl/Cl) which were quite close to their theoratical values.