Applications Of Raman Spectroscopy To Detection Of Drug And Food Safety

The phenomenon that the light deviates from its original propagating direction and spreads in all directions when passes though the inhomogeneous medium is called light scattering. The Indian scientist Raman gets the relevant information of the molecular structure so as to apply it to the qualltative detection because of the changes of the direction and energy of light when the incident light irradiates the sample, who called the analytic method as Raman spectrometry.The discovery, theory, characteristics and applications of Raman, and the enhanced mechanism and applications of surface-enhanced Raman spectroscopy(SERS) have been reported in this paper; Dexamethasone Sodium Phosphate(DsP), Betamethasone Sodium Phosphate(BsP) and Sudan Red have been investigated by Raman spectrometry and SERS. The main research contents are as follows:(l)The methods of preparation and processing of the silver colloidal substrate, and the preparation of Cu-Ag nanocomposite material were discussed. The results showed that the signal peaks of the sample has been enhanced, and long life cycle, steady enhance.(2) Infrared spectroscopy (FTIR) of the two epimers DSP and BSP, normal Raman spectroscopy (NRS) of the solids and saturated solutions and the saturated solutions of SERS on the silver colloidal substrate were investigated. Results:the major differences between the two similar substances were the frequency of the CH3asymmetric stretching vibration and symmetric in-plane deformation vibration of them. According to the mechanism and laws of the SERS, the epimers were absorbed on the silver colloid through the P-O bond, carboxyl group and five-membered ring perpendicularly.(3) The calculation of molecular structures, Raman and infrared spectroscopy of the illegal food additives of Sudan Red substances by density functional theory (DFT), and the determining of Raman, infrared spectroscopy and SERS of Cu-Ag nanocomposite material substrate as well as the comparative study on the three above spectra were investigated. The major vibrational peaks were assigned by the software of Gauss view5.0.