The Elementary Study On The Chinese Famous Liquor By Spectral Methods

The Chinese famous liquor, as the world-famous brand, has been receiving the infringement of the false famous brand all the time. Nowadays, people pay more and more attention to how to distinguish the Chinese famous brands of wine. There are mainly two kinds of methods to distinguish famous liquor: One method is to distinguish the liquor by the sense organ, and the other method is to adopt chromatograms analysis. But the former is time-consuming, arduous and costly, which limits its application in industrial production and circulation. Searching for simple and rapid appraisal method will be valuable in distinguishing high-quality Chinese liquor from fake or inferior brands.A large number of reports find: all kinds of Chinese famous liquor contain almost the same perfume components, but there are obvious differences between quantity and proportion of perfume. Obviously, it is unrealistic and unnecessary for quantitative analysis of several hundred kinds of chemical components in Chinese liquor. It is just significative for quantitative analysis of those perfume-decising compositions, which is chemically steady and determine the liquor flavor of the Chinese famous liquor. Chinese scientific researchers have analyzed the 30 kinds of main chemical components by GC/MS, GC/IR and other advanced analyzing methods. From the flavoring components of famous Chinese liquor, Chinese researchers put forward"chromatograph skeleton components", which determine the aroma and quality of liquor. It provides potential evidence for the determination of aroma, commonness and differences of Chinese famous liquor. Also, it makes it feasible to blend and appreciate liquor by computer. Spectrum analytic approach has already applied to research fields such as material, chemistry, living beings, mineral gem, law sciences of public security for its fast and unharmful properties at present. This text has studied on the Moutai liquor by UV-Vis-NIR absorption, infrared and Raman spectra in order to obtain its chromatogram property and appreciate the true and false Moutai liquor. We find that the furfural content in Moutai is 10 times more than that of other famous brands of liquor by the spectral analysis, so we have chosen furfural, one of the most important perfume compositions in the Moutai, as the research object.Raman scattering is one method to investigate molecular vibrations. The principle and mechanism of Raman scattering is different from infrared spectrum, but the information they offer is complemental. They both offer information about various normal vibration frequencies and correlated vibrational energy level in the molecule. They can both be used to identify the functional group that exist in the molecule. In the analysis of molecular structure, Raman and infrared spectra supplement each other. As a result, some information that can't be measured in infrared spectrum can well show in Raman spectrum. Raman spectrum is used along with infrared spectrum offer more comprehensive information of molecular structure. Surface enhanced Raman scattering, which has extremely high sensitivity and can offer molecular structure information, especially the information of mutual interaction between the molecules and metal surface, has been widely applied in trace detection. Density functional theory (DFT) is the third method (except ab initio method and semiempirical method ) of the computation of molecular structure and vibrational frequencies. DFT methods have led to the prediction of very accurate molecular structures and vibrational frequencies as compared to the conventional ab initio and semiempirical methods. The DFT method provides a costeffective approach for calculating the vibrational spectra of molecules. The DFT method has been extensively used in fields such as chemistry, physics, life sciences and material science at present.This paper has studied the spectrum of the Moutai liquor. The paper is made up of four parts as follows:One: summary of the Chinese famous brand of liquor. This part introduces appraisal method of famous liquor, component, micro-perfume composition, fragrant type, detection method and achievement of the Chinese famous brand and furfural made in the past. Also, we briefly introduce the application of Raman scattering and surface enhanced Raman technique in unharmful detection.Two: the elementary study on Moutai spectrum method is presented in this part. We investigated the true and false Moutai by UV-Vis-NIR, Raman and Surface enhanced Raman spectra method. The results show it is feasible for distinguishing the true and false Moutai by spectrum method.Three: We calculated the Raman and IR spectra of furfural molecule by DFT method and compare them with the normal Raman and infrared spectra obtained in our experiment. Also, the vibrational modes of spectra were assigned and ascribed. Four: this part investigated the furfural molecule absorded on the surface of silver colloid and silver mirror by surface enhanced Raman spectrum method. By the comparision analysis of the calculated and experimental results, it is concluded that furfural molecules are perpendicularity or acclivitously adsorded on the silver surface via the nonbonding electrons of the carbonyl oxygen. Meanwhile, we have studied SERS spectra of furfural molecule absorded on the surface of copper electrode under different voltages. The experimental results showed that the absorded manners of furfural molecule varied with change of the electrode voltage.