红外谱的样品制备-液体和固体
Sample Preparation for IR Spectra - Liquids & Solids
Bio-Rad's laboratories have prepared and analyzed thousands of samples by means of infrared spectroscopy. These samples range from commercial products like polymer beads and liquid surfactants to high purity organic compounds suitable for their standards collection. A wide variety of techniques have been developed by spectroscopists and spectral technicians in order to obtain high-quality infrared spectra from these diverse materials. The purpose of this Application Note is to communicate Bio-Rad’s knowledge of infrared sample preparation to you. In this Application Note, selection of technique based on physical characteristics of the sample will be discussed.
The information desired from a spectrum largely determines how the compound is to be prepared for examination. A
compound in the crystalline state generally yields a spectrum which has more absorption bands than the spectrum of the same compound when examined in the liquid state or in solvent solution. The absorption bands in the spectrum of a solid compound, examined in the crystalline state, or a liquid compound, examined in the pure concentrated form (neat), are found, usually, at lower frequencies than the absorption bands in the spectrum of the same compound when it is examined in the vapor state or in solvent solution. The degree of absorption band shifts depends upon the presence or absence of intermolecular and intramolecular forces.