Fourier transform infrared spectroscopy sample preparation

FIGURE 26 Fourier transform infrared spectroscopy of polymer samples prepared at either 130, 145, or 160°C with or without cyclo-benzaprine hydrochloride (CBP). Polymer prepared from 3,9-bis-(ethylidene-2,4,8,10-tetraoxaspiro[5,5)undecane) and a 25 75 mole ratio of trans-cyclohexane dimethanol and 1,6-hexanediol and contained 3 wt% phthalic anhydride and 7.5 wt% cyclobenzaprine hydrochloride (CBP). 

Recently, we reported that an Fe supported zeolite (FeHY-1) shows high activity for acidic reactions such as toluene disproportionation and resid hydrocracking in the presence of H2S [1,2]. Investigations using electron spin resonance (ESR), Fourier transform infrared spectroscopy (FT-IR), MiJssbauer and transmission electron microscopy (TEM) revealed that superfine ferric oxide cluster interacts with the zeolite framework in the super-cage of Y-type zeolites [3,4]. Furthermore, we reported change in physicochemical properties and catalytic activities for toluene disproportionation during the sample preparation period[5]. It was revealed that the activation of the catalyst was closely related with interaction between the iron cluster and the zeolite framework. In this work, we will report the effect of preparation conditions on the physicochemical properties and activity for toluene disproportionation in the presence of 82. ... 

Sampling in surface-enhanced Raman and infrared spectroscopy is intimately linked to the optical enhancement induced by arrays and fractals of hot metal particles, primarily of silver and gold. The key to both techniques is preparation of the metal particles either in a suspension or as architectures on the surface of substrates. We will therefore detail the preparation and self-assembly methods used to obtain films, sols, and arrayed architectures coupled with the methods of adsorbing the species of interest on them to obtain optimal enhancement of the Raman and infrared signatures. Surface-enhanced Raman spectroscopy (SERS) has been more widely used and studied because of the relative ease of the sampling process and the ready availability of lasers in the visible range of the optical spectrum. Surface-enhanced infrared spectroscopy (SEIRA) using attenuated total reflection coupled to Fourier transform infrared spectroscopy, on the other hand, is an attractive alternative to SERS but has yet to be widely applied in analytical chemistry. 

Bulk samples of CWC-related chemicals are analyzed with minimum sample preparation by Fourier transform infrared spectroscopy (see... 

Fourier transform infrared spectroscopy (FTIR) was also used to monitor the degree of pyrolysis for various samples at different temperatures. The KBr (potassium bromide) pellet of sample was prepared for FTIR analysis. 

Fourier-transform infrared spectroscopy (FTIR) and pH measurements are the techniques most often adapted for in-line IPC. pH measurements are used for reactions that are run in water or have an aqueous component, e.g., an aqueous extraction. FTIR is especially good for monitoring continuous reactions [12] and reactions that would be dramatically changed by exposure to the atmosphere and temperature of the laboratory. Suitable reactions include low-temperature reactions, reactions run under pressure, reactions with gaseous or toxic materials (e.g., ethylene oxide), and reactions run under inert atmosphere. Further advantages of in-line assays are that no samples need to be prepared, and assay results can be generated within minutes. 

FT-IR spectroscopy. Fourier Transform Infrared Spectroscopy was performed with the use of the Perkin-Elmer 1600 series FT-IR or Digilab FTS-60 spectrometer. A minimum of 64 scans at a resolution of 2 cm was signal-averaged. Samples for FT-IR studies were prepared by casting blend solutions onto KBr windows followed by vacuum drying at 80 °C for 3 days. For the precipitated inter-polymer complexes, KBr discs were prepared. 

To determine the polymer(s) that are present in a rubber it is usual to use either Fourier-transform infrared spectroscopy or nuclear magnetic resonance (NMR) spectroscopy. These techniques are normally applied to a sample that has undergone some preliminary preparation. For example, a solvent extraction can be carried out to remove process oils and other low-Mw organic compounds and then the extracted sample is often pyrolysed to remove any interferences from the fillers present. As solid-state NMR techniques become more advanced and sensitive, however, it may become easier to obtain this information directly on samples in the future. 

The mixture is stimed under He flow and the temperature is increased to 343 K. Then, water is added in small doses at 30 minutes intervals the water to Ti(OR>4 ratio being of 30. After that, the mixture is kept under reaction for 4 h. The sample is filtered, washed with ethanol and dried at 383 K overnight. The support prepared using this procedure is denoted as Si-Ti and is characterized by therm analysis (TG). An aliquot of this support is calcined at 723 K for 24 h leading to Si-Ti-C support. Fourier Transform Infrared Spectroscopy (FTIR) is carried out on self-supported wafers. The spectra are recorded on a Nicolet 5 ZDX spectrophotometer equipped with an MCT (mercuiy-cadmium-tellnride) detector with a resolution of 4 cm. ... 

Several additional instrumental techniques have also been developed for bacterial characterization. Capillary electrophoresis of bacteria, which requires little sample preparation,42 is possible because most bacteria act as colloidal particles in suspension and can be separated by their electrical charge. Capillary electrophoresis provides information that may be useful for identification. Flow cytometry also can be used to identify and separate individual cells in a mixture.11,42 Infrared spectroscopy has been used to characterize bacteria caught on transparent filters.113 Fourier-transform infrared (FTIR) spectroscopy, with linear discriminant analysis and artificial neural networks, has been adapted for identifying foodbome bacteria25,113 and pathogenic bacteria in the blood.5... 

Chemical and instrumental (e.g., chromatography and mass spectrometry) methods have provided valuable information that lead to the advancement of cheese science. However, these techniques suffer from one or more of the following problems (1) the extensive use of solvents and gases that are expensive and hazardous, (2) high costs, (3) the requirement of specific accessories for different analytes, (4) the requirement of extensive sample preparation to obtain pure and clean samples, and (5) labor-intensive operation. These disadvantages have prompted for the evaluation and adoption of new, rapid, and simple methods such as Fourier-transform infrared (FTIR) spectroscopy. Many books are available on the basics of FTIR spectroscopy and its applications (Burns and Ciurczak, 2001 Sun, 2009). FTIR spectroscopy monitors the vibrations... 

In contrast, diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy allows one to monitor solid-state structural changes. It is specifically designed to study powder samples, and is well known for its high sensitivity. A wide variety of materials can be analyzed using DRIFT spectroscopy. Some materials can be analyzed neat, without any sample preparation, but polymers have to be diluted normally by embedding them into a matrix. 

It would be most desirable to study lipid oxidation in intact food products without the extraction or sample preparation steps currently necessary (e.g., pelletization, freeze-drying). Perhaps improvements in techniques such as the Fourier transform infrared photoacoustic spectroscopy (Yang and Irudayaraj, 2000) will open such possibilities. 

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