甲基对硫磷溶液的荧光光谱及其特性————

为了研究甲基对硫磷溶液的荧光光谱及其特性,采用多功能光谱测量系统,对甲基对硫磷标准溶液在紫外光激励下的荧光光谱特性进行了实验研究。利用GAUSSIAN软件与量子力学理论进行了理论分析,获得了其荧光光谱的产生机理以及甲基对硫磷分子的相应跃迁能级差,估算了其中直线型结构的荧光团的电子跃迁能级差,估算值与理论值误差不大。结果表明,在波长为200nm～320nm的紫外光激励下,甲基对硫磷标准溶液产生4个荧光峰,分别位于435nm,467nm,567nm,650nm,最佳激励波长为200nm和295nm。4处荧光峰分别是溶剂丙酮分子中C=O上的n电子跃迁、硝基上的n电子跃迁、甲基对硫磷分子中氧原子与苯环形成的大共轭电子结构跃迁以及P=S上的n电子跃迁共同作用产生。以上结果对食品安全监管等领域检测有机磷农药含量是有帮助的。

Fluorescence Spectra of Methyl Parathion and its Characteristic

Using SP-2558 multifunctional spectrometer system, the spectral characteristic of methyl parathion standard solution induced by UV-light has been experimentally studied with the fluorescence spectra. The results show that there are four fluorescence peaks generated when methyl parathion standard solution is excited by UV light with the wavelength of 200 nm~320 nm. The peak position is located at 435 nm, 467 nm, 567 nm and 650 nm separately. The best excitation wavelength is 200 nm and 295 nm. The four fluorescence peaks are generated separately by the combined actions of the methyl parathion and the acetone. In methyl parathion molecule, there are the transition of n electrons in nitryl, the transition of π electronic structure formed by the oxygen atom and the benzene ring and the transition of n electrons in P=O group. In acetone molecule, there is the transition of n electrons in C=O group. Then the characteristic and the mechanism of the fluorescence spectra of methyl parathion standard solution are explained. In addition, the transition energy of methyl parathion is calculated, and the transition energy of the linear structure fluorophore is estimated by using the methods of quantum mechanics.