联苯菊酯是一种Ⅰ型拟除虫菊酯农药, 因药效好, 作用迅速, 易降解等优点而被广泛地应用于农业生产中。 但联苯菊酯农药残留对有益昆虫, 水生动物有致死毒性, 对人类具有内分泌干扰作用, 雌激素效应, 并能存留于肝脏等多种器官, 对人体健康有严重危害。 密度泛函理论是一种量子力学从头计算方法, 可以用来计算分子轨道和拉曼光谱。 结合密度泛函理论和拉曼光谱研究物质是当前最为常用的拉曼光谱研究方法。 采用密度泛函理论的B3LYP/6-31G基组, 对联苯菊酯分子构型进行优化并计算了其理论拉曼光谱。 在实验中采用波长为785 nm激光作为激发光, 获得了联苯菊酯分析纯固体的自发拉曼光谱。 将联苯菊酯理论拉曼光谱和实验拉曼光谱对比分析, 对联苯菊酯分子的振动模式进行分析和归属, 联苯菊酯分子结构相对复杂, 振动模式较多, 拉曼峰复杂繁多, 找到了位于659, 948, 993和1 292 cm-1处拉曼活性相对较强的峰作为鉴别联苯菊酯的特征峰, 并可以根据这些特征峰对联苯菊酯分子进行定性定量分析。 研究结果表明, 联苯菊酯的理论拉曼光谱和实验拉曼光谱具有较好的匹配性, 但二者在特征峰的波数上存在一定程度的偏移。 这是由于理论计算考察的对象为联苯菊酯的气态单分子, 而联苯菊酯固体中存在复杂的分子间作用和基团间相互作用。 当前对联苯菊酯的分子振动模式和拉曼光谱研究相对较少, 且联苯菊酯农药残留也是近年来备受关注的问题, 研究结果将为联苯菊酯农药残留的定性定量分析提供了一种新的可行方法, 并为作物表面农药残留快速检测奠定基础。

Bifenthrin is a type Ⅰ pyrethroid pesticide, which is widely used in agricultural production due to its good efficacy, rapid action and easy degradation. However, bifenthrin pesticide residues have lethal toxicity to beneficial insects, aquatic animals, endocrine disrupting effects on humans, estrogen effects, and persistence in multiple organs such as the liver, which are seriously harmful to human health. Density functional theory is a mathematical ab initio calculation method that can be used to calculate molecular orbitals and Raman spectra. Density functional theory is a mathematical ab initio calculation method that can be used to calculate molecular orbitals and Raman spectra. Combining density functional theory and Raman spectroscopy to study materials is currently the most commonly used Raman spectroscopy research method. In this paper, the B3LYP/6-31G basis set of density functional theory was used to optimize the molecular configuration of bifenthrin and calculate its theoretical Raman spectrum. In the experiment, a laser having a wavelength of 785 nm was used as the excitation light, and a spontaneous Raman spectrum of the pure solid of bifenthrin analysis was obtained. By comparing the theoretical Raman spectroscopy and experimental Raman spectroscopy of bifenthrin, the vibration mode of bifenthrin molecules is analyzed and attributed. The molecular structure of bifenthrin is relatively complex, it has more vibration mode, and the Raman peak is more complicated. A peak with relatively strong Raman activity at 659, 948, 993 and 1 292 cm-1 was found as a characteristic peak for the identification of bifenthrin, and the bifenthrin molecules can be qualitatively and quantitatively classified according to these characteristic peaks. The results show that the theoretical Raman spectra of bifenthrin and the experimental Raman spectroscopy have good matching, but there is a certain degree of shift in the wave number of the characteristic peaks. This is due to the fact that the object of the theoretical calculation is the gaseous monomolecular of bifenthrin, and the complex intermolecular interaction and inter-group interaction exist in the bifenthrin solid. At present, there are relatively few studies on the molecular vibration mode and Raman spectroscopy of bifenthrin, and the bifenthrin pesticide residue has also attracted much attention in recent years. The research results provide a qualitative and quantitative analysis of bifenthrin pesticide residues. A new feasible method and lay the foundation for rapid detection of pesticide residues on crop surfaces.