FTIR spectroscopy, analytical method

Analytical investigations may be undertaken to identify the presence of an ABS polymer, characterize the polymer, or identify nonpolymeric ingredients. Fourier transform infrared (ftir) spectroscopy is the method of choice to identify the presence of an ABS polymer and determine the acrylonitrile—butadiene—styrene ratio of the composite polymer (89,90). Confirmation of the presence of mbber domains is achieved by electron microscopy. Comparison with available physical property data serves to increase confidence in the identification or indicate the presence of unexpected stmctural features. Identification of ABS via pyrolysis gas chromatography (91) and dsc ((92) has also been reported. 

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... 

The fact that fluorination had taken place was established by various analytic methods ESCA, IR and FTIR spectroscopy, bulk anlaysis,NMR, and DSC. The presence of chemically bonded fluorine in the surface layer of treated samples were uniquely determined by analysis data. Further details can be found elsewhere.22... 

To put things into perspective, we. can broadly classify these analytical methods into bulk, dry surface, and in situ interfacial techniques. This chapter focuses on the last category, illustrating two in situ techniques used to study anion binding at the goethite (a-FeOOH)-water interface titration calorimetry and cylindrical internal reflection-Fourier transform infrared (CIR-FTIR) spectroscopy. In fact, CIR-FTIR could prove to be extremely powerful, since it allows direct spectroscopic observation of ions adsorbed at the mineral-water interface. 

Fourier transform infrared (FTIR) spectroscopy of coal low-temperature ashes was applied to the determination of coal mineralogy and the prediction of ash properties during coal combustion. Analytical methods commonly applied to the mineralogy of coal are critically surveyed. Conventional least-squares analysis of spectra was used to determine coal mineralogy on the basis of forty-two reference mineral spectra. The method described showed several limitations. However, partial least-squares and principal component regression calibrations with the FTIR data permitted prediction of all eight ASTM ash fusion temperatures to within 50 to 78 F and four major elemental oxide concentrations to within 0.74 to 1.79 wt % of the ASTM ash (standard errors of prediction). Factor analysis based methods offer considerable potential in mineral-ogical and ash property applications. 

FTIR Fourier transform infrared spectroscopy has been used for many years to measure atmospheric gases. Because FTIR has become such a common analytical method, we do not describe the technique itself here but rather refer the reader to several excellent books and articles on the subject (e.g., see Griffiths and de Haseth, 1986 Wayne, 1987). For reviews of some atmospheric applications, see Tuazon etal. (1978,1980), Marshall et al. (1994), and Hanst and Hanst (1994). 

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... 

Fourier transform infrared (FTIR) spectroscopy An analytical method that uses infrared radiation to investigate the chemical characteristics of a sample. This method may be used to identify the valence states of arsenic on adsorbents and bonds between arsenic and other elements (e.g. (Goldberg and Johnston, 2001)) (compare with Raman spectroscopy). 

In the case of an unknown chemical, or where resonance overlap occurs, it may be necessary to call upon the full arsenal of NMR methods. To confirm a heteronuclear coupling, the normal H NMR spectrum is compared with 1H 19F and/or XH 31 P NMR spectra. After this, and, in particular, where a strong background is present, the various 2-D NMR spectra are recorded. Homonuclear chemical shift correlation experiments such as COSY and TOCSY (or some of their variants) provide information on coupled protons, even networks of protons (1), while the inverse detected heteronuclear correlation experiments such as HMQC and HMQC/TOCSY provide similar information but only for protons coupling to heteronuclei, for example, the pairs 1H-31P and - C. Although interpretation of these data provides abundant information on the molecular structure, the results obtained with other analytical or spectrometric techniques must be taken into account as well. The various methods of MS and gas chromatography/Fourier transform infrared (GC/FTIR) spectroscopy supply complementary information to fully resolve or confirm the structure. Unambiguous identification of an unknown chemical requires consistent results from all spectrometric techniques employed. 

The results are reported of a study of plate-out in PVC extrusion carried out using several analytical techniques, including DSC, SEM-EDX, FTIR spectroscopy and laser ionisation mass spectrometry. A special die and calibrator unit developed to investigate plate-out are illustrated and the reproducibility of the method evaluated. The effects of water content and anti-plate-out additives, such as alumina and silica, on plate-out are discussed and mechanisms explaining the formation of plate-out are proposed. 11 refs. 

Fourier transform infrared (FTIR) and in-situ FTIR spectroscopy are among many modern instrumental tools of analytical chemistry well established in fuel-cell-related electrochemistry [1]. In general, FTIR spectroscopy is a valuable tool in the characterization of fuel cell technical electrodes, where the nature of surface groups can be identified, since such electrodes are rather difficult solid surfaces on which to work. FTIR is among the methods less commonly used for the characterization of dispersed catalysts and supports, but as a technique is able to give an idea about the nature of the surface groups on carbon supports and on the structure of adsorbed species on noble metal clusters. 

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