Use of infrared spectroscopy

Positive identification of synthetic fibers can be made using standard analytical methods published by AATCC (American Association of Textile Chemists and Colorists), ASTM (American Society of Testing Materials) and The Textile Institute, Manchester. 

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Igniters, Incendiaries, Boosters, and Delay Compositions on a Micro Scale by Use of Infrared Spectroscopy , FrankfordArs Rept T-71-6-1 (1971) 8) G.A. St John M. 

The use of infrared spectroscopy of adsorbed molecules to probe oxide surfaces has been reviewed by Davydov and Rochester [23], This approach works on sulfide catalysts as well. The infrared signal of NO has been successfully used to identify sites on the surface of a hydrodesulfurization catalyst, as the following example shows [24]. 

L.G. and Novikova, G.A. (1992) Use of infrared spectroscopy for the determination of some properties of soil. In Murray, I. and Cowe, I.A. (eds) Making Light Work Advances in Near Infrared Spectroscopy. VCH, Weinheim, Germany, pp. 239-249. 

One of the main routine uses of infrared spectroscopy is identification of specific functional groups present in an unknown molecule and, as a result, further characterization of the unknown. By far the most common example involves the carbonyl group. Location of a strong band in the infrared in the vicinity of 1730cm is almost certain proof that carbonyl functionality is present. This confidence is based on the fact that the characteristic frequency (the CO stretch in this case) is isolated, that is to say, it is sufficiently far removed from the other bands in the infrared spectrum to not be confused with them. It also assumes that carbonyl groups in different chemical environments will exhibit similar characteristic... 

The usefulness of infrared spectroscopy of proteins and membranes is increased when spectra of dry films are compared with those taken in deuterium oxide. Exchange of protons for deuterons can affect both the amide I and amide II bands. For randomly coiled proteins in D20 the amide I band is shifted down by about 10 cm."1 but for many proteins D20 does not affect the frequency of the carbonyl stretch of either the ft structure or the a-helix. In addition, upon complete exchange the amide... 

The widespread use of infrared spectroscopy at that time was probably due to the observation that many chemical groups absorb in a very narrow range of frequency. Furthermore, within this frequency range, the observed frequency may be correlated to specific chemical structures. For example, aldehydes can be differentiated from ketones by the characteristic stretching frequency of the carbonyl group near 1700 cm-1, and the spectral pattern may be likened to a molecular fingerprint. ... 

The classical approach to the analysis of mixtures by use of infrared spectroscopy consists in identifying specific, strong bands that belong to a suspected component, obtain a pure spectrum of the suspected component, and then remove those in the spectrum of the mixture that are due to the identified compound. The process is repeated for the remaining bands in the mixture spectra. Once the component spectra are known for a mixture, a series of calibration curves is produced. These curves relate concentration to absorbance, using Beer s law. The concentration of the components of the mixture are then obtained by interpolation. The advantage of Fourier-transform, infrared spectroscopy is that components of a mixture may be... 

FT-IR diffuse reflectance measurements have been used to quantitatively determine the amount of silane deposited on a substrate. The advantages of FT-IR are speed and sensitivity, the latter relating to the ultimate analytical precision or the smallest amount of the analyte one can determine. Other classical uses of infrared spectroscopy are as a qualitative identification or structure elucidation tool. 

The development of Fourier transform techniques with infrared spectra has made the use of infrared spectroscopy available to many more polymer chemists. 

The following part of this review article consists of four sections. Section 2 is concerned with infrared and AFM studies of Langmuir-Blodgett (LB) films. This section contains introductory parts for infrared and AFM studies of monolayers. This section also emphasizes the importance of combined use of infrared spectroscopy and AFM. LB films of 2-alkyl-7,7,8,8-tetracyanoqui-nodimethane (alkyl-TCNQ) are taken up as examples. Section 3 outlines SERS studies of monolayers. This section describes the usefulness and uniqueness of SERS in the investigations of LB and self-assembled monolayer (SAM) films. Following this section, we present other AFM studies on monolayers in Section 4. In Section 5 infrared and visible spectroscopy studies on J- and H-aggregates in LB films of mecrocyanine dye are reported. 

Yang,T. H., Dong, A., Meyer, J., Johnson, O. L., Cleland, J. L., and Carpenter, J. F. (1999), Use of infrared spectroscopy to assess secondary structure of human growth hormone within biodegradable microspheres,/. Pharm. Sci., 88,161-165. 

Gloor, M., Hirsh, G. and Willebrandt, U. On the use of infrared spectroscopy for the in vivo measurement of the water content in the homy layer after application of dermatological ointments. Archives of Dermatological Research 271 305-314, 1981. 

The present chapter deals with the use of infrared spectroscopy in radiation chemistry. After an historical introduction and the presentation of the basic knowledge needed in infrared spectroscopy, we describe the major milestones of its implementation within that field. Section 3 describes the use of infrared spectroscopy in astrophysics. Starting in the 1980s, such studies aim at characterizing the sample s modifications after irradiation. Section 4 describes the implementation of infrared reflection-absorption spectroscopy (IR-RAS) and its use in understanding the radiation-induced surface chemistry. Section 5 is focused on the chemistry induced by swift heavy ions in polymers. Section 6 presents recent developments that enable us to perform... 

This Chapter will deal with the use of infrared spectra in ascertaining some of the configurational and structural aspects of various carbohydrate molecules. It must be realized at the outset that the use of infrared spectroscopy in this field is a useful tool for the chemist but should not be considered as supplanting the classical chemical methods for determining these particular entities. 

We have expanded coverage of spectroscopy in several ways. Chapter 4 introduces the use of infrared spectroscopy, especially its applications to carbonyl complexes. C-13 and H-l nuclear magnetic resonance spectroscopy are emphasized in Chapter 5 and P-31 NMR is introduced in Chapter 6. New to the second edition is the inclusion of a section on mass spectroscopy in Chapter 6. Chapters 4-6 contain numerous end-of-chapter problems, where spectroscopic information is an essential part of the exercise. Subsequent chapters have additional spectroscopy problems. 

The use of infrared spectroscopy, either through fingerprint characterisation or by functional group identification, is well established. IR vibrational spectroscopy has thus been applied in spectroelectrochemistry for quite some time. ° The possibility to establish the symmetry of a molecule has made IR-SEC a most valuable tool for mixed-valence chemistry, ° allowing intramolecular electron-transfer rates in the picosecond region to be assessed and electron-transfer isomers to be established. ... 

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