Terahertz Spectroscopic Investigation of Organophosphorus Pesticide Parathion-Methyl
YAN Zhi-gang1,2, ZHENG Song1, XIE Qiang-jun1, ZHOU Ze-kui2
1. School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018 China 2. Research Center for Terahertz Technology, College of Info Science and Engineering, Zhejiang University, Hangzhou 310027, China
Abstract：The present paper reports the theoretical and experimental vibrational spectra of organophosphorus pesticide parathion-methyl in the frequency range from 0.2 to 2.0 THz respectively. Under the room temperature and nitrogen conditions, the absorption peaks were found at 0.65, 1.33, 1.81 and 1.91 THz, and the average refractive index was 1.39 based on the terahertz time-domain spectroscopy (THz-TDS). In parallel with the experimental study, density functional theory (DFT) was applied to obtain the structure and vibrational frequencies of parathion-methyl in the terahertz region. The calculated results are in reasonable agreement with the experimental data. The absorption features are caused by the collective vibrational and torsional modes, and the different absorption peaks correspond to different vibrational modes.
Key words：Terahertz time-domain spectroscopy;Absorption coefficient;Parathion-methyl;Density functional theory
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