Kang Xu-Sheng, Zhang Guang-Xin, Chen Xi-Ai, Huang Ping-Jie, Hou Di-Bo, Zhou Ze-Kui
Department of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2011 Oct;31(10):2629-33.
The optical properties of elaidic acid in the THz band were investigated by using THz time-domain spectroscopy (THZ-TDS). The absorption and refractive index spectra in the frequency range from 0.5 to 2.5 THz were obtained at room temperature under nitrogen atmosphere, and the results show that elaidic acid had some characteristic absorption peaks, and the average refractive index of the sample was 1.43. The structure and vibrational frequencies of elaidic acid molecule in the THz range were simulated by the B3LYP algorithm of density functional theory, and the THz characteristic absorption peaks of elaidic acid molecule were identified by using Gaussian View software. The results show that the experimental and theoretical results agree in general, and the observed absorption peaks in the THz range were mainly caused by the intramolecular and intermolecular vibrations jointly. At the same time, the fingerprint spectra of elaidic acid in the THz band verify that the time-domain terahertz spectroscopy can be used to detect oleic acid, and this study provides a new experimental method for the detection of trans fatty acids in food.
采用太赫兹时域光谱（THZ-TDS）研究了反油酸在太赫兹波段的光学性质。在氮气气氛下室温获得了0.5至2.5太赫兹频率范围内的吸收光谱和折射率光谱，结果表明反油酸有一些特征吸收峰，样品的平均折射率为1.43。利用密度泛函理论的B3LYP算法模拟了反油酸分子在太赫兹范围内的结构和振动频率，并使用Gaussian View软件识别了反油酸分子的太赫兹特征吸收峰。结果表明，实验结果与理论结果总体一致，太赫兹范围内观察到的吸收峰主要是由分子内和分子间振动共同引起的。同时，反油酸在太赫兹波段的指纹光谱验证了时域太赫兹光谱可用于检测油酸，本研究为食品中反式脂肪酸的检测提供了一种新的实验方法。
