Diffuse reflectance Fourier-transform application

Berben SA, Rademacher JP, Sell LO, Easty DB (1987) Estimation of lignin in wood pulp by diffuse reflectance Fourier-transform infrared spectrometry Tappi J 70(11) 129-133 Birkett M, Gambino M, Meyer JH, Egers D (1989) Estimation of kappa number of pulps by near-infrared spectroscopy Tappi J 72(9) 193-197 Bracewell R (1965) The Fourier transformation and its applications McGraw-Hill, New York, 381 pp... 

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... 

Infrared (IR) spectroscopy is most often used for qualitative identification of chemical compounds. Comprehensive works on the application of IR spectroscopy to identification of surfactants are available elsewhere. The volume of Hummel is an essential reference for experts as well as a teaching aid for novices (1). The Sadtler database is invaluable (2). A number of shorter works provide an introduction to surfactants for the beginner (3-6). With experience, the spectroscopist will find it possible to identify not only pure compounds, but also mixtures of surfactants. Modem computerized instraments aid by permitting subtraction of spectra of known compounds from the spectrum of the mixture. IR spectroscopy is widely used for detailed examination of purified fractions prepared by extraction or ion exchange chromatography. The small sample size requirement makes it possible to identify compounds collected from the eluent of a liquid chromatograph, especially if techniques like diffuse reflectance Fourier transform IR are used. 

Diffuse Reflectance, Attenuated Total Reflection or Multiple Internal Reflection, Photoacoustic (PAS), Photothemal Beam Deflection, Specular Reflection Absorption, and forensic applications with the diamond cell and the Fourier transform infrared (FTIR) microscope. In museum laboratories, FTIR applications have been used for problems of identification and degradation in art and archeology. (14)... 

Ferraro JR, Nakamoto K (1994) Introductory Raman Spectroscopy, Academic Press, New York Ferraro JR, Rein AJ (198.5) Applications of Diffuse Reflectance Spectroscopy in the Far-Infrared Region. In Ferraro JR, Basile LJ (eds) Fourier Transform Infrared Spectroscopy, vol 4. Academic, Orlando... 

This paper presents examples of the application of diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy to the study of acid site chemistry and catalysis by product-selective molecular sieve materials. The most attractive features of the DRIFT method are that (i) uncompacted, high-surface-area powders can be studied in controlled chemical environments and over a wide range of temperatures (ii) reactants can be passed through a bed of the powdered sample and infrared spectra recorded simultaneously at temperatures in excess of 500 C with high species detection sensitivity and (iii) the sample can be repeatedly regenerated and exposed to reactants without being removed from the diffuse reflectance (DR) cell assembly. 

Lennard C J, Mazzella W D and Margot P A 1993 Some applications of diffuse reflectance infrared Fourier transform spectroscopy DRIFTS in forensic science Analysis 21 M34-7... 

B.K. Alsberg. W.G. Wade and R. Goodacre. Chemometric Analysis of Diffuse reflectance-absorbance Fourier Transform Infrared Spectra Using Rule Induction Methods Application to the Classification of Eubacterium Species, Applied Spectroscopy, 52(6) (1998), 823-832. 

Mitchell, M. B. (1993) Fundamentals and applications of diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. AC5 Advances in Chemistry Series 236,351-375. 

Figure 8.6 Diffuse reflectance infrared spectra of (a) form I and (b) form II of cortisone acetate [4]. Reprinted from Spectrochim. Acta, 47A, Deeley, C. M., Spragg, R. A. and Threlfall, T. L., A comparison of Fourier transform infrared and near-infrared Fourier transform Raman spectroscopy for quantitative measurements an application in polymorphism , 1217-1223, Copyright (1991), with permission from Elsevier.

Different characterization techniques are used to get an insight into the location of transition metal ions in an aluminophosphate framework. Generally, the data on the cation location are collected with difficulty since the metal concentration is low. In this regard, it is necessary to use more than one method if a reliable conclusion is to be reached (ie, the simultaneous application of several physical techniques is recommended). The following characterization methods are commonly applied diffuse reflectance UV-vis spectroscopy (DRS), electron spin resonance (ESR), electron spin echo modulation (ESEM), infrared (IR), and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies, as well as the nuclear magnetic resonance spectroscopy (NMR), Mossbauer spectroscopy and the X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption spectroscopy for fine structure (EXAFS) (167,168) and references therein). 

The structurally related ri-form has received less study [58,59] but in both cases it has been concluded that three different types of surface Lewis site - strong, medium, and weak - are present. Our initial examinations (Figures 7.7 and 7.8) of activated tj-alumina, by observing desorption of a saturated chemisorbed py overlayer, through diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) observation of the py 8a mode band intensity at various temperatures, were in accord with this view [60]. The application of inelastic... 

With the advent of the commercial FT-IR instruments, and computer techniques, it is now possible to record the infrared spectrum of almost any material regardless of its shape or form. A number of different sampling accessories are available for recording the infrared spectra. Some of these accessories such as AIR and specular reflectance have been used successfully with dispersive instruments, but the FT-IR instruments allow these accessories to be used more rapidly and with greater sensitivity. Most of the sample handling techniques have been reviewed in detail in the series of volumes on "Fourier Transform Infrared Spectroscopy" edited by J.R. Ferraro and J.R. Basile (1). In this paper, some of these techniques will be reviewed with particular emphasis on reflectance techniques (ATR and diffuse) and photoacoustic spectroscopy. Further applications such as far-IR, diamond cell, the absorption subtraction methodology can be found in the article by Krishnan and Ferraro (2). 

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