酸性橙Ⅱ在食品工业中是禁用添加剂。针对酸性橙Ⅱ的食品安全检测问题,报道了运用荧光光谱技术检测其水溶液的实验。实验表明,酸性橙Ⅱ水溶液在230～290 nm波长激发下,310～390 nm范围内产生荧光光谱,峰位波长在350nm,最佳激励波长为250nm;采用垂直偏振片(起偏角为00)起偏照射样品,发现偏振荧光峰位不变,荧光峰强度随检偏角的增大而呈明显的线性递减关系。由实验数据计算得到荧光偏振度为0.783,表明分子具有一定确定取向;另外,分析认为酸性橙Ⅱ产生荧光,是由于分子中含有苯环和萘环结构吸收紫外光能量,以及氮键在光子作用下形成顺式异构体的激发单线态后,两者发射的光子所致。整个结果对酸性橙Ⅱ在食品中的违禁使用检测、特性表征、以及分子规律的更深入研究,有一定的参考价值。

Acid orange Ⅱ is forbidden in food industry. For food security detection of acid orange Ⅱ, the experiment based on fluorescence spectra is reported. The result shows that the emitted fluorescence range is 310～390 nm when the sample is excited by ultraviolet radiation in 230～290 nm, the peak wavelength is 350 nm, and the best excitation wavelength is 250 nm. The polarized fluorescence peak is constant, when a vertical polarizer is used. The intensity of fluorescence spectrum decreases in a linear law, with polarization angle increasing, and the polarization degree is calculated as 0.783. The orientation characteristics of molecule are considered. Moreover, analysis shows that the existence of structure of benzene and naphthalin in molecule is a reason of fluorescence, and single-line excitated state of nitrogen-bond by exciting light is another. The research can contribute to the detection of food security characteristic experssion, study of characterization of acid orange Ⅱ.