太赫兹技术对二氯苯胺两种同分异构体的检测

采用太赫兹时域光谱技术测量了3,4-二氯苯胺和2,5-二氯苯胺在0.2~2 THz波段的吸收谱，3,4-二氯苯胺在1.00 THz,1.48 THz,1.88 THz处有3个吸收峰，2,5-二氯苯胺在0.83 THz,1.04 THz,1.17 THz处有3个吸收峰，吸收峰峰位强度也有明显不同。采用密度泛函理论进行理论光谱计算，理论光谱与实测光谱一致性良好。结果表明通过太赫兹时域光谱技术可以实现3,4-二氯苯胺和2,5-二氯苯胺2种同分异构体的指纹检测，为太赫兹波段有明显特征吸收峰的毒性物质检测提供了一种快速、准确的方法。

Detection of two isomers of dichloroaniline by terahertz time-domain spectroscopy

Terahertz time-domain spectroscopy is utilized to detect the spectra of 3,4-dichloroaniline and 2,5-dichloroaniline isomers within the spectral range of 0.2 to 2 THz. There are absorption peaks at 1.00, 1.48 and 1.88 THz in the spectra of 3,4-dichloroaniline, comparing with absorption peaks at 0.83, 1.04 and 1.17 THz in the spectra of 2,5-dichloroaniline. The intensity of the absorption peaks for the two isomers are also obviously different. DFT(Density Functional Theory) is adopted to simulate the theoretical spectrum of two isomers, which indicates the theoretical spectra and experimental spectra are in good consistency. The results reveal that terahertz time-domain spectroscopy can be applied in the fingerprint detection of 3,4-dichloroaniline and 2,5-dichloroaniline isomers. It provides a rapid and accurate method for the detection of toxic compounds which have obvious absorption peaks in terahertz band.