Some Applications Of IR Spectra In Analyzing The Unknown Materials

In this dissertation, three kinds of oat products which belong to two brands have been distinguished by Fourier Transform Infrared Spectra (FTIR). The chemical compositions of two unknown paints have been tested by FTIR, and then we have determined the solvents and the basic material through analyzing the IR spectra. Researched the surfactant of a kind of softener of clothes, and we get its structure by analyzing its spectrum.The dissertation is divided into 4 chapters. In Chapter 1, we introduce the development and applications of the FTIR; and the work we have done in this dissertation and their practicality. In Chapter 2, after analyzing the IR spectra of three kinds of oat products which belong to two brands, we can find the fingerprint characteristics of the main nutritious components, such as lipoid (1747, 2855 and 2927cm^-1), protein (1658 and 1540cm^-1), and carbohydrate (1200-900cm^-1). For the same kind of samples made in different factories, there are certain similarities in the IR spectra, however, the second derivative infrared spectra present different fingerprint characteristics and the similar IR spectra can be distinguished. In Chapter 3 and Chapter 4, we have tested IR spectra of the solvents and the basic material of two unknown paints by FTIR. First we can deduce the possible compositions of the two paints from analyzing the fingerprint characteristics, and then compare with GC-MS data and the standard IR spectra; at last, we determine components of the solvent and basic material. The first one is short-oil alkyd resin paint, and its solvents are toluene, dimethylbenzene, ethylbenzene and some other poisonous volatile organic compounds; the basic material is short-oil alkyd resin. The second one is nitro colophony paint, and its solvents are mixture of alcohol, mixture of ester, dimethylbenzene, ethylbenzene and some other poisonous aromatic organic compounds; the basic materials are nitrocellulose and alkyd resin. In Chapter 5, A surfactant was isolated from a kind of softener of clothes by extraction, and then speculated it was quaternary ammonium salt by testing its infrared spectrogram and analyzing the major absorption peak, at last confirm the surfactant was Dimethyl dioctadecyl ammonium bromide after the analysis of nuclear magnetic resonance(NMR).