苹果汁中吡蚜酮农药残留荧光检测研究

Fluorescence Detection of Pymetrozine Pesticide Residues in Apple Juice

摘要: 本文利用LS55荧光分光光度计对苹果汁与吡蚜酮混合体系进行了荧光光谱检测，发现在355 nm处有明显的吡蚜酮药物特征峰，从而得到苹果汁中不同农药含量的荧光光谱图。其次对果汁–农药的混合体系的荧光发射谱进行回归分析建模，得出荧光强度与农药浓度之间的预测模型函数并对其进行分析。最后通过回收率计算该混合体系的相对标准偏差来进一步验证实验的准确性。结果表明：当292 nm作为激发波长时，纯苹果汁在355 nm处没有特征荧光峰出现，而有吡蚜酮的苹果汁在355 nm处有很强的荧光特征峰。苹果汁中吡蚜酮预测模型函数为y = −107.89188 × exp(−x/0.0018) + 112.26682，其相关系数是0.9994，农药含量与荧光强度的模型函数回收率在90%~105%范围内，平均回收率为96.5%，相对标准偏差为3.18%。

Abstract: The fluorescence spectrophotometer was used to detect the fluorescence spectrum of the mixed system of apple juice and pymetrozine. It was found that there was an obvious characteristic peak of the drug in 355 nm, and the fluorescence spectrum of different pesticide content in apple juice was obtained. Secondly, the fluorescence emission spectrum of the mixed system of juice and pesticide was regressed with the results being obtained. The prediction model function between the fluorescence intensity and the concentration of pesticides is analyzed. Finally, the relative standard deviation of the mixed system is calculated by the recovery rate to further verify the accuracy of the experiment. The results show that when 292 nm is used as the excitation wavelength, the pure apple juice is not at 355 nm. There were characteristic fluorescence peaks in apple juice with pymetrozine and strong fluorescence peaks in 355 nm. The prediction model function of pymetrozine in apple juice is y = −107.89188 × exp (−x/0.0018) + 112.26682 with the correlation coefficient of the model function of pymetrozine in apple juice being 0.9994 and the recovery was in the range of 90% - 105%. The average recovery was 96.5% and the relative standard deviation was 3.18%.