Fourier Transform-infrared Applications

Ferraro JR, Basile LJ (1978) Fourier transform infrared application to national problems In Ferraro JR, Basile U (eds) Fourier transform infrared spectroscopy - applications to chemical systems, Vol 4 Academic Press, New York, 275-302 Ferraro JR, Rein AJ (1985) Application of diffuse reflectance spectroscopy in the far-infrared region In Ferraro JR, Basile LJ (eds) Fourier transform infrared spectroscopy -applications to chemical systems, Vol 4 Academic Press, New York, 244-282 Frank IE, Feikema J, Constantine N, Kowalski BR (1984) Prediction of product quality from spectral data using the partial least squares method J Chem Inf Comput Sci 24 20-24 Fuller MP, Griffiths PR (1980) Infrared microsampling by diffuse reflectance Fourier transform spectrometry Appl Spectrosc 34 533-539... 

Fourier transform infrared (FTIR) analyzers can be used for industrial applications and m situ measurements in addition to conventional laboratory use. Industrial instruments are transportable, rugged and relatively simple to calibrate and operate. They are capable of analyzing many gas components and determining their concentrations, practically continuously. FTIR analyzers are based on the spectra characterization of infrared light absorbed by transitions in vibrational and rotational energy levels of heteroatomic molecules. 

In the following, some examples of applications of Fourier transform infrared (FTIR) Spectroscopy and of solid-state nuclear magnetic resonance (NMR) to the study of polymorphism in polymers are described. 

Recent work in our laboratory has shown that Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) can be used routinely to measure vibrational spectra of a monolayer on a low area metal surface. To achieve sensitivity and resolution, a pseudo-double beam, polarization modulation technique was integrated into the FT-IR experiment. We have shown applicability of FT-IRRAS to spectral measurements of surface adsorbates in the presence of a surrounding infrared absorbing gas or liquid as well as measurements in the UHV. We now show progress toward situ measurement of thermal and hydration induced conformational changes of adsorbate structure. The design of the cell and some preliminary measurements will be discussed. 

Time-resolved Fourier transform infrared spectroscopy has been used surprisingly little considering the nuadter of commercial spectrometers that are currently in laboratories and the applicability of this technique to the difficult tine regime from a few is to a few hundred is. One problem with time-resolved Fourier transform spectroscopy and possibly one reason that it has not been more widely used is the stringent reproducibility requirement of the repetitive event in order to avoid artifacts in the spectra( ). When changes occur in the eiaissirr source over the course of a... 

A significant advance was the application of the Fourier transform technique to enhance the signal. The optical arrangement of a Fourier transform infrared (FUR) spectrometer is shown in Fig. 27.37 (Habib and Bockris, 1984). A beam of light from an IR source is directed to a beamsplitter, where part of the beam is transmitted to a... 

At present, most workers hold a more realistic view of the promises and difficulties of work in electrocatalysis. Starting in the 1980s, new lines of research into the state of catalyst surfaces and into the adsorption of reactants and foreign species on these surfaces have been developed. Techniques have been developed that can be used for studies at the atomic and molecular level. These techniques include the tunneling microscope, versions of Fourier transform infrared spectroscopy and of photoelectron spectroscopy, differential electrochemical mass spectroscopy, and others. The broad application of these techniques has considerably improved our understanding of the mechanism of catalytic effects in electrochemical reactions. 

W. Herres, "HRGC-FTIR Capillary Gas Chromatography-Fourier Transform Infrared Spectrometry. Theory and Applications", Huethlg, Heidelberg, 1987. 

R. White, "Chromatography/Fourier Transform Infrared Spectroscopy and Its Applications", Dekker, New York, NY, 1990. 

Figure 7.10 Typical optical arrangements employed for detection of (a) vapour phase (b) liquid phase and (c) solid chromatographic phases. After White [167], Reprinted from R. White (ed.), Chromatography/Fourier Transform Infrared Spectroscopy and Its Applications Marcel Dekker Inc., New York, NY (1990), by courtesy of Marcel Dekker Inc.

W. Herres, HRGC-FTIR Capillary Gas Chromatogra-phy-Fourier Transform Infrared Spectroscopy, Theory and Applications, Huthig Publishers, Heidelberg (1987). 

Ferraro, J.R. and Basilo, L.J. (1978, 1979) Fourier Transform Infrared Spectroscopy Application to Chemical Systems, New York Academic Press, Vols 1 and 2. 

McGovern, A. C. Ernill, R. Kara, B. V. Kell, D. B. Goodacre, R. Rapid analysis of the expression of heterologous proteins in Escherichia coli using pyrolysis mass spectrometry and Fourier transform infrared spectroscopy with chemometrics Application to a2- interferon production. J. Biotechnol. 1999, 72,157-167. 

Several modem analytical instruments are powerful tools for the characterisation of end groups. Molecular spectroscopic techniques are commonly employed for this purpose. Nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and mass spectrometry (MS), often in combination, can be used to elucidate the end group structures for many polymer systems more traditional chemical methods, such as titration, are still in wide use, but employed more for specific applications, for example, determining acid end group levels. Nowadays, NMR spectroscopy is usually the first technique employed, providing the polymer system is soluble in organic solvents, as quantification of the levels of... 

Miniaturized chemical analysis systems have been developed for most macroscopic counterparts (Dittrich et al. 2006). The availability of optical fibers, light sources, and detectors in the visible UV and near-infrared (NIR) wavelengths makes it possible to integrate spectroscopic measurements in microreactors (Lobbecke et al. 2005). Fourier transform infrared spectroscopy (FTIR) is an efficient, broadly applicable... 

The application of Fourier-transform infrared spectroscopy of polymers has been reviewed. Since the requirements for activity of a vibration for causing absorption in the infrared and for causing... 

In Chapter 12, the use of mass spectrometry and Fourier transform infrared spectrometry (FTIR) for GC detection was discussed. Details of these techniques were individually given in Chapters 10 and 12. Much of the discussion presented in Chapter 16 is applicable here. Both liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-infrared spectrometry (LC-IR) have been adapted to HPLC detection in recent years. 

NMR) [24], and Fourier transform-infrared (FT-IR) spectroscopy [25] are commonly applied methods. Analysis using mass spectrometric (MS) techniques has been achieved with gas chromatography-mass spectrometry (GC-MS), with chemical ionisation (Cl) often more informative than conventional electron impact (El) ionisation [26]. For the qualitative and quantitative characterisation of silicone polyether copolymers in particular, SEC, NMR, and FT-IR have also been demonstrated as useful and informative methods [22] and the application of high-temperature GC and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is also described [5]. 

The infrared technique has been described in numerous publications and recent reviews were published by Davies and Giangiacomo (2000), Ismail et al. (1997) and Wetzel (1998). Very few applications have been described for analysis of additives in food products. One interesting application is for controlling vitamin concentrations in vitamin premixes used for fortification of food products by attenuated total reflectance (ATR) accessory with Fourier transform infrared (FTIR) (Wojciechowski et al., 1998). Four vitamins were analysed - Bi (thiamin), B2 (riboflavin), B6 (vitamin B6 compounds) and Niacin (nicotinic acid) - in about 10 minutes. The partial least squares technique was used for calibration of the equipment. The precision of measurements was in the range 4-8%, similar to those obtained for the four vitamins by the reference HPLC method. 

Titration calorimetry and cylindrical internal reflection-Fourier transform infrared (CIR-FTIR) spectroscopy are two techniques which have seldom been applied to study reactions at the solid-liquid interface. In this paper, we describe these two techniques and their application to the investigation of salicylate ion adsorption in aqueous goethite (a-FeOOH) suspensions from pH 4 to 7. Evidence suggests that salicylate adsorbs on goethite by forming a chelate structure in which each salicylate ion replaces two hydroxyls attached to a single iron atom at the surface. 

With the recent progress in Fourier transform infrared (FTIR) spectroscopy, quantitative estimates of the various functional groups can also be made. This is particularly important for application to the higher-molecular-weight solid constituents of petroleum (i.e., the asphaltene fraction). 

Infrared (IR) spectroscopy offers many unique advantages for measurements within an industrial environment, whether they are for environmental or for production-based applications. Historically, the technique has been used for a broad range of applications ranging from the composition of gas and/or liquid mixtures to the analysis of trace components for gas purity or environmental analysis. The instrumentation used ranges in complexity from simple filter-based photometers to optomechanically complicated devices, such as Fourier transform infrared (FTIR) spectrometers. Simple nondispersive infrared (NDIR) insttuments are in common use for measurements that feature well-defined methods of analysis, such as the analysis of combustion gases for carbon oxides and hydrocarbons. For more complex measurements it is normally necessary to obtain a greater amount of spectral information, and so either Ml-spectrum or multiple wavelength analyzers are required. 

NMR spectroscopy is relatively insensitive compared to optical spectroscopies such as Fourier transform infrared, requiring acquisitions of several minutes to obtain high signal-to-noise ratio spectra adequate for process analytical applications. The linear response and low sensitivity of NMR also prevents its use for observing very low level contaminants (<1000ppm) in complex mixtures. 

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