溶液的酸碱性对番茄红素荧光光谱的影响

The Influence of Acid and Alkali on the Fluorescence Spectrum of Lycopene

用970CRT荧光分光光度计分别采集了不同pH值下番茄红素-丙酮溶液的荧光光谱,并测量了这些溶液的荧光强度随时间的变化情况。通过对数据的分析得出:与没有经过酸碱滴定的番茄红素-丙酮溶液相比,酸性条件下,荧光强度相对较小,而在碱性条件下,其荧光强度相对较大;pH=1时,番茄红素-丙酮溶液的荧光峰位发生了红移,而pH=11和pH=13时,其荧光峰位又有不同程度的蓝移;在强酸和强碱环境中番茄红素不稳定,其荧光峰强度下降较快,这是因为在强酸环境下重原子效应的影响,和强碱环境下番茄红素参加了阴离子聚合反应;番茄红素在有机溶剂和弱碱环境下比较稳定,其荧光强度下降较慢。

By using 970CRT fluorescence spectrophotometer,the fluorescence spectra of lycopene-acetone solution with different pH have been collected,and these fluorescence intensities versus time have been measured.After analysis these data,the conclusion was obtained： the fluorescence intensities of the lycopence were relatively stronger under alkali circumstance than under acid circumstance.Red shift occurred when pH=1,and different blue shifts occurred when pH=11 and pH=13.Under strong acid and alkali circumstance,lycopene was very unstable,and it＇s fluorescence intensity dropped dramatically,the reasons were that the weight atom effect influenced the flurescence spectra under acid circumstance and lycopene took part in the negative ion polymerization under strong alkali circumstance.In organic solvent and under feeble alkali circumstance,lycopene was relatively stable,the change of the fluorescence intensities was not strong.