二噁英是目前已知的最具毒性的物质，通常产生于燃烧及工业生产过程，难以降解，因此对其进行检测尤为重要。红外光谱法根据分子的红外吸收特性反演组分的浓度，在小分子中已经得到了很好的研究和应用。目前尚缺少有关二噁英红外光谱参数的信息。为实现采用光谱法测量二噁英的浓度，首先需要对二噁英的光谱进行研究。采用Gaussian 09软件包对2，3，7，8-四氯代二苯并对二噁英（TCDD）分子进行光谱计算；采用VERTEX 80型傅里叶变换红外光谱仪对质量浓度分别为30，40，50 μg/mL的2，3，7，8-TCDD分子光谱在1600~1000 cm-1范围进行测量，仪器的分辨率为4 cm-1，扫描次数为16；在297 K下，对2，3，7，8-TCDD分子在1466 cm-1处的谱线强度进行了测量。结果表明： 2，3，7，8-TCDD分子的最强吸收峰位于1466 cm-1附近，这是由于苯环振动引起的，理论计算与实验得到的光谱对应性较好。该研究为今后实现红外光谱吸收法测量2，3，7，8-TCDD分子浓度提供了光谱信息，具有重要的理论意义。

Dioxin is the most toxic chemicals known at present, it is usually generated in combustion and industrial production processes, and it is difficult to degrade, therefore, it′s particularly important for its detection. Infrared spectroscopy can retrieve component concentration based on infrared absorption characteristics of molecules, which has been widely researched and applied in small molecules. At present, there is no information about the parameters of dioxin infrared spectrum, in order to measure the concentration of dioxin by spectroscopy, firstly, we need to study the spectrum of dioxin. The spectral calculation of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) molecule is carried out with Gaussian 09 software package. The VERTEX 80 Fourier transform infrared spectrometer is used to measure the 2, 3, 7, 8-TCDD molecule spectrum in the range of 1600-1000 cm-1 under different concentrations of 30 μg/mL, 40 μg/mL, and 50 g/mL, respectively. The resolution of the instrument is 4 cm-1 and the scanning times is 16. In addition, the spectral intensity of 2, 3, 7, 8-TCDD molecule at 1466 cm-1 is measured at 297 K. The results show that the maximum absorption peak of 2, 3, 7, 8-TCDD molecule is located near 1466 cm-1, this is caused by the vibration of benzene ring. It has good correspondence of spectra obtained by theoretical calculation and experiment. This study provides spectral information for the measurement of 2, 3, 7, 8-TCDD molecule concentration by infrared absorption spectrometry, and has important theoretical significance.