Fourier transform spectrophotometer

The infrared absorbance spectra were recorded at room temperature on a Fourier transform spectrophotometer (Biucker I.F.S. 110) with a resolution of 4 cm To compare the integrated adsorbances of the various samples the weight of the pellet and the Pd content were considered. The samples were placed in a heatable cell where the catalysts were treated "in situ". Different kinds of experiments were carried out ... 

Spectra were obtained using a Digilab FTS-15E Fourier Transform Spectrophotometer. A NaCl crystal mounted in a heated cell (Model 018-5322 Foxboro/Analabs, N. Haven, Ct.) was placed in the infrared beam and the chamber allowed to purge for several minutes while the cell was brought to the desired temperature. The temperature of the cell was controlled using a DuPont 900 Differential Thermal Analyzer interfaced to the spectrometer cell. A chlorobenzene solution (ca. 10 by wt.) of the sample was then applied to the crystal using cotton tipped wood splint. 

The heart of a Fourier transform infrared spectrophotometer is the interferometer in Figure 20-26. Radiation from the source at the left strikes a beamsplitter, which transmits some light and reflects some light. For the sake of this discussion, consider a beam of monochromatic radiation. (In fact, the Fourier transform spectrophotometer uses a continuum source of infrared radiation, not a monochromatic source.) For simplicity, suppose that the beamsplitter reflects half of the light and transmits half. When light strikes the beamsplitter at point O, some is reflected to a stationary mirror at a distance OS and some is transmitted to a movable mirror at a distance OM. The rays reflected by the mirrors travel back to the beamsplitter, where half of each ray is transmitted and half is reflected. One recombined ray travels in the direction of the detector, and another heads back to the source. 

McCarthy, W.J. and Kemeny, G.J., Fourier Transform Spectrophotometers in the Near-Infrared. In Burns, D.A. and Ciurczak, E.W. (eds), Handbook of Near-Infrared Analysis, 2nd Edn Marcel Dekker, Inc. New York, 2001 pp. 71-90. 

Sadtler Collection. The most comprehensive collection of published spectra is that of the SadU Researdi Laboratories. Li the solid liquid phases, over 63 000 spectra of pure compounds including 600 spectra of commonly abused ugs, 600 spectra of pieptoxic chemicals have been published, in addition to 36 000 spectra of commercud products. There are also 7400 spectra in the vapom phase. Mpropriate Fourier transform spectrophotometer. 

H21. Horlick, G., and Malmstadt, H. V., Basic and practical considerations for sampling and digitising interferograms generated by a Fourier-transform spectrophotometer. Anal. Chem. 42, 1361-1369 (1970). 

Aspects of construction and specific features of operating mode for Fourier transform spectrophotometers (FTIR)... 

We have two types of IR sp>ectrophotometers The classical and the Fourier Transform spectrophotometers with the interferometer... 

Spectra were obtained at a resolution of 4 cm with a Digilab FTS-15E Fourier Transform spectrophotometer. Thirty scans were co-added to produce one spectrum. A reference spectrum of the NaCl salt crystal was collected before the material to be analyzed... 

Less reveahng are the ir spectra of larger peptide molecules. Unless sophisticated instruments, such as high resolution Fourier-transform spectrophotometers are applied, the large amide absorption overshadows other carbonyl frequencies. In some special cases, however, ir spectra can be uniquely informative. For example esterification of the phenolic hydroxyl in tyrosine with sulfuric acid is best revealed through the characteristic ir spectrum of sulfate esters, clearly distinguishable from the spectrum of the sulfonic acid derivatives which are the potential by-products of the sulfation process. 

We have modified an NIR Fourier-transform spectrophotometer (JEOL JIR-5500) for the measurements of Raman spectra excited with the 1064-nm line of a continuous-wave Nd YAG laser (CVI YAG-MAX C-92) [60]. Raman-scattered radiation is collected with a 90° off-axis parabolic mirror in a back-scattering geometry. Collected radiation is passed through two or three long-wavelength-pass filters to reduce the Rayleigh scattering. 

Fig. 3. Fourier transform spectrophotometer (interferometer) optical configuration.

Interferometers (Fig. 4) provide the main optical element for Fourier-transform infrared spectrophotometry. Interferometer-based Fourier-transform spectrophotometers are extremely accurate in the frequency scale... 

Outlines of the synthetic routes used to obtain the desired polymers are shown in figures 1 and 2. After each step each compound was purified to a sharp melting point. Each new compound was identified by NMR and IR spectroscopy. NMR spectra were run using a Varian A-60 spectrometer. IR spectra were run on KBr pellets using a Digilab FTS-14 Fourier Transform Spectrophotometer. 

FTIR Measurements. As to the polypeptide-containing block copolymer, the polymer film was formed on a Pt mesh (10 x 10 mm, 60 mesh) by dip coating and treated similarly to that on the electrode. Transmission spectra of the treated film were taken on a Nicolet 510M Fourier transform spectrophotometer. The infrared spectra were measured at 2 cm resolution and signal-averaged over 1024 scans. 

Lanthanum monochloride LaCl has been less studied. Xin and Klynning (1994) reported molecular constants obtained from analysis of the rotational structure of IR bands in the thermal emission spectrum of LaCl recorded on a high-resolution Fourier transform spectrophotometer. It is worth noting that, despite a rather strong emission spectrum of LaCl, Xin and Klynning (1994) failed to detect the absorption spectrum of this compound. In this context, these authors selected, with low confidence and, apparently by analogy with the conclusions of Schall et al. (1983), the... 

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