利用荧光分光光度计对典型食品果汁（苹果汁和桃汁）与百菌清混合体系进行了荧光光谱检测, 发现在352 nm处有明显百菌清药物特征峰。 对混合体系的荧光发射光谱和其导数光谱进行回归分析建模, 得到果汁中百菌清浓度和荧光强度之间的预测模型函数。 在两种光谱模式下所建指数预测模型函数相关系数都高于0.99, 优于线性模型函数; 针对两种果汁, 原始光谱模式下所建指数模型函数平均回收率分别为101%和100%, 线性模型平均回收率分别为110%和118%; 导数光谱模式下, 两种果汁中百菌清指数函数预测模型平均回收率分别为101%和102%, 而线性模型平均回收率分别为109%和120%。 研究结果表明可以通过荧光光谱法直接实现果汁中百菌清残留检测, 且指数函数预测模型优于线性模型, 同时表明在果汁-百菌清混合体系的农药残留定量预测中, 导数荧光光谱方法并无显著优势, 可直接选用荧光原始光谱建模分析。

Fluorescence spectrum of mixed solution between chlorothalonil and typical fruit juice (apple juice and peach juice) were obtained with fluorescence spectrophotometer. It was found that there was a characteristic peak in 352 nm of chlorothalonil. Regression analysis was applied in the modeling of relationship between fluorescence intensity and chlorothalonil concentration. Estimation function of chlorothalonil concentration was deduced through fluorescence spectrum and its derivative fluorescence spectrum. The correlation coefficients of the exponential prediction model under two kinds of spectral patterns were higher than 0.99, which was better than the linear function model. For the two kinds of fruit juice, the average recoveries of the exponential model function under the original spectral pattern were 101% and 100% while the average recoveries of the linear model were 110% and 118%, respectively; The average recoveries of the exponential model function under the derivative spectral mode were 101% and 102%, and the average recoveries of the linear model were 109% and 120% respectively. The analysis results showed that fluorescence spectrometry can be used to detect and predict the chlorothalonil residue in fruit juice, and the performance of established exponential function model was better than the linear function model. At the same time, derivative fluorescence spectrometry method was found to have no significant advantage in the concentration prediction model of chlorothalonil residue in fruit juice, so the original fluorescence spectrum can be directly applied in the modeling analysis.