The Study of Raman Spectroscopy of Bifenthrin Molecular

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.