利用分光光度计, 通过对多菌灵及橙汁-多菌灵混合体系的紫外-可见吸收光谱进行研究, 得到橙汁中不同农药含量下的吸收光谱特征, 分析了吸光度与多菌灵农药含量的关系。 研究表明: 多菌灵药液在285 nm处有较强的特征吸收峰。 通过向橙汁中逐量添加028 mg·mL-1多菌灵标准溶液, 与纯多菌灵药液吸收光谱比较, 发现峰值位置出现了小幅度蓝移(285～280 nm), 说明橙汁和多菌灵发生了相互作用, 通过对280 nm波长处的吸光度与多菌灵药液含量进行最小二乘法线性拟合, 建立了橙汁中吸光度与多菌灵农药含量之间的预测模型, 发现吸光度与多菌灵药剂含量具有很好的线性关系, 其线性函数模型为: I=241+926x, 相关系数为0996, 回收率在81%～102%之间。 根据该回归模型, 可以得到橙汁中多菌灵农药残留量的准确值, 从而验证了利用紫外-可见吸收光谱测定橙汁中多菌灵残留量的方法的可行性。 研究表明, 利用光谱技术直接对果汁中农药残留检测方法是可行的, 能够满足快速分析的需要, 本研究为农药残留检测提供了新的途径。

Absorption spectra were studied for the carbendazim, in the mixed solution of orange juice and carbendazim using spectrophotometer. The most intensive characteristic peak (285 nm) was found in the spectrum of carbendazim standard solution. Compared with the carbendazim drug solution, the peak position of absorption spectrum has the blue shift(285～280 nm)when carbendazim(0.28 mg·mL-1)was added in the orange juice. So that we can conclude that interaction happened between the orange juice and carbendazim. Through the method of least squares fitting, the prediction models between the absorbance of orange juice and carbendazim content was obtained with a good linear relationship. The linear function model was: I=2.41 +9.26x, the correlation coefficient was 0.996, and the recovery was: 81%～102%. According to the regression model, we can obtain the amount of carbendazim pesticide residues in orange juice. It was verified that the method of using ultraviolet-visible absorption spectra was feasible to detect the carbendazim residues in orange juice. The result proved that it is possible to detect pesticide residues of carbendazim in orange juice, and it can meet the needs of rapid analysis. This study provides a new way for the detection of pesticide residues.