Infrared spectrophotometer Fourier transform

D Commercial COTS controlled by external computer Hybrid systems such as automated dissolution workstation with high-performance liquid chromatography (HPLC) or ultraviolet-visible (UV-Vis) interface Liquid chromatographs, gas chromatographs, UV/Vis spectrophotometers, Fourier transform infrared (FTIR) spectrophotometers, near-infrared (NIR) spectrophotometers, mass spectrometers, atomic absorption spectrometers, thermal gravimetric analyzers, COTS automation workstations... 

Willey R R 1976 Fourier transform infrared spectrophotometer for transmittance and diffuse reflectance measurements Appl. Spectrosc. 30 593-601... 

Two common detectors, which also are independent instruments, are Fourier transform infrared spectrophotometers (FT-IR) and mass spectrometers (MS). In GC-FT-IR, effluent from the column flows through an optical cell constructed... 

Co concentration was determined by spectrophotometer (Varian Cary 500) at 692 nm wave length, with the sample diluted with a 9 mol/L concentrated HCl solution. NO content in gas phase was obtained by an on-line Fourier transform infrared spectrometer (Nicolet E.S.P. 460 FT-IR) equipped with a gas cell and a quantitative package, Quant Pad. 

Xiao H-K, Levine SP, D Arcy JB, et al. 1990. Comparison of the Fourier transform infrared (FTIR) spectrophotometer and the Miniature Infrared Analyzer (MIRAN ) for the determination of trichloroethylene (TCE) in the presence of Freon -113 in workplace air. Am Ind Hyg Assoc J 51 395-401. 

F.C. Strong III, How the Fourier transform infrared spectrophotometer works. J. Chem. Educ., 56(1979) 681-684. 

Perhaps the most widely and commonly used method for liquid sampling, used with Fourier transform infrared (FTIR) spectrophotometers, is... 

We have seen in the previous section that Raman spectra are complementary to infrared spectra. Both spectroscopies provide quite useful information on the phonon structure of solids. However, infrared spectra correspond to a range from about 100 cm to about 5000 cm that is, far away from the optical range. Thus, infrared absorption spectra are generally measured by so-called Fourier Transform InfraRed (FTIR) spectrometers. These spectrometers work in a quite different way to the absorption spectrophotometers discussed in Section 1.3. 

XANES and EXAFS were conducted at BL-lOB in the Photon Factory of the National Laboratory for High Energy Physics (KEK-PF)[12]. s Fe Nttssbauer spectra were recorded with a Shimadzu MEG-2 spectrometer(13]. Isomer shifts were given relative to a-Fe. Infrared spectra were recorded by a Shimadzu Fourier-transform infrared spectrometer(FTIR-4100) with a resolution of 2 cm i. Diffuse reflectance UV-VIS spectra were obtained on a Hitachi 330 spectrophotometer. 

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. 

The interferometer mirror of a Fourier transform infrared spectrophotometer travels 1 cm. 

Since the article by Spedding1 on infrared spectroscopy and carbohydrate chemistry was published in this Series in 1964, important advances in both infrared and Raman spectroscopy have been achieved. The discovery2 of the fast Fourier transform (f.F.t.) algorithm in 1965 revitalized the field of infrared spectroscopy. The use of the f.F.t., and the introduction of efficient minicomputers, permitted the development of a new generation of infrared instruments called Fourier-transform infrared (F.t.-i.r.) spectrophotometers. The development of F.t.-i.r. spectroscopy resulted in the setting up of the software necessary to undertake signal averaging, and perform the mathematical manipulation of the spectral data in order to extract the maximum of information from the spectra.3... 

NMR spectra in D20 were recorded on a Bruker WM-360 NMR spectrometer. IR spectra were recorded neat with liquids or as fluorolube mulls with solids using a Nicolet 20DXB Fourier Transform Infrared Spectrophotometer. 

X-ray photoelectron spectroscopy (XPS) was used for elemental analysis of plasma-deposited polymer films. The photoelectron spectrometer (Physical Electronics, Model 548) was used with an X-ray source of Mg Ka (1253.6 eV). Fourier transform infrared (FTIR) spectra of plasma polymers deposited on the steel substrate were recorded on a Perkin-Elmer Model 1750 spectrophotometer using the attenuated total reflection (ATR) technique. The silane plasma-deposited steel sample was cut to match precisely the surface of the reflection element, which was a high refractive index KRS-5 crystal. 

Fourier transform infrared (FTIR) spectroscopy has been extensively developed over the past decade and provides a number of advantages. The main part of FTIR spectrophotometer is the Michelson interferometer. Radiation containing all IR wavelengths (e.g., 4000-400 cm 1) is emitted by source of infrared radiation (Globar) and is split into two beams. One beam is of fixed length, and the other is of variable length (movable mirror). 

All infrared spectra were recorded with an IR-PLAN microscope (IR-PLAN is a registered trade mark of Spectra Tech, Inc.) integrated to a Perkin-Elmer Model 1800 Fourier transform infrared (FT-IR) spectrophotometer. The spectrophotometer consisted of a proprietary heated wire source operated at 1050°C, a germanium overcoated potassium bromide beamsplitter, and a narrow-band mercury-cadmium-telluride (HgCdTe) detector. The detector was dedicated to the microscope and had an active area of 250 x 250 pm. The entire optical path of the system microscope was purged with dry nitrogen. 

All of the infrared experiments were performed on a Digilab FTS-40 Fourier transform infrared (FT-IR) spectrometer equipped with a narrow-band liquid-nitrogen-cooled mercury-cadmium-telluride (MCT) detector. The spectrometer was operated at a nominal resolution of 4 cm-1 using a mirror velocity of 1.28 cm/s. The data collected using the gas chromatography (GC) IR software were measured at 8 cm-1 resolution. Protein assays for all the experiments were measured on a Beckman DU-70 UV-visible spectrophotometer. 

The samples of free lipase, pure silica (PS), silanized and activated silica, and immobilized derivatives were submitted to the Fourier Transform Infrared Spectroscopy (FTIR) analysis (Spectrophotometer FTIR BOMEM MB-100). The spectra were obtained in the wavelength range of 400-4000 cm-1 for evaluation of the immobilization procedures. 

It should be possible to see the chemical products in the infrared spectra of the thin film. In order to look at the small quantities of material involved, it was necessary to do in situ exposures of the resist coatings on silicon wafers in a Fourier transform infrared spectrophotometer. The technique was capcUsle of following the loss of quinone and the formation of ketene with considerable success. By purging the wafer in the chamber for some time in the presence of dry nitrogen, it was possible to observe a stable ketene signal even hours after the exposure. While these experiments were not quantitative, they did give two pieces of... 

Three types of infrared instruments are found in modem laboratories dispersive spectrometers (or spectrophotometers), Fourier-transform (FTIR) spectrometers, and fdter photometers. The first two are used for obtaining complete spectra for quali-... 

The titanium contents of the resulting catalyst samples were determined with an inductively coupled plasma-atomic emission spectrometer (ICP-AES) (Kon-tron, Germany Model S-35) after HE acid digestion of the solid. N2 adsorption/ desorption isotherms at 77 K were obtained using a Micromeritics ASAP 2020 apparatus. Catalyst crystalline structure was examined by X-ray diffraction (XRD) on a Shimadzu XRD-6000 diffractometer with Cu Ka radiation. X-ray photoelectron spectroscopy (XPS) data were acquired on a VG Microtech MT-500 spectrometer using A1 Ka X-ray radiation (1,486.6 eV). Fourier transform infrared (FUR) data were obtained on a Shimadzu IR Prestige FUR spectrophotometer. 

Characterization of catalysts The zeolite structure was checked by X-ray diffraction patterns recorded on a CGR Theta 60 instrument using Cu Ka, filtered radiation. The chemical composition of the catalysts was determined by atomic absorption analysis after dissolution of the sample (SCA-CNRS, Solaize, France). Micropore volumes were measured by N2 adsorption at 77 K using a Micromeritics ASAP 2000 apparatus and by adsorption of cyclohexane (at P/Po=0.15) using a microbalance apparatus SET ARAM SF 85. Incorporation of tetrahedral cobalt (II) in the framework of Co-Al-BEA and Co-B-BEA was confirmed by electronic spectroscopy [18] using a Perkin Elmer Lambda 14 UV-visible diffuse reflectance spectrophotometer. Acidity measurements were performed by Fourier transform infrared spectroscopy (FT-IR, Nicolet FTIR 320) after pyridine adsorption. Self-supported wafer of pure zeolite (20 mg/cm ) was outgassed at 673 K for 6 hours at a pressure of lO Pa. After cooling at 423 K, the zeolite was saturated with pyridine vapour (30 kPa) for 5 min, evacuated at this temperature for 30 min and the IR spectrum was recorded. 

Figure 10.10 Fourier transform infrared spectrophotometer. The optical bench of the 380 FTIR, equipped with a diamond ATR accessory (reproduced courtesy of Nicolet).

Degradation was followed by measuring the infrared absorption intensities of the aliphatic and sulfone groups in the chain as a function of dose. Measurements were made on a Perkin Elmer Model 257 grating spectrophotometer and by Fourier Transform infrared spectrometry using a Nicolet 5DX FTIR spectrometer operating at 2 cm-1 resolution. Absorbance spectra of PMPS in novolac/PMPS blends were corrected for the contribution due to novolac absorption by subtraction of an appropriately scaled absorbance spectrum of pure novolac. 

Tenn. Electronic spectroscopy was performed on a Varian Cary 17 recording spectrophotometer and a Nicolet Fourier Transform Infrared instrument was used to record spectra between 4000 and 200 cm l of samples in Csl. Electrical measurements were performed at room temperature on compacted samples by a four probe technique. TGA was performed on a DuPont 990 Analyzer using a DuPont 951 TGA module. TGA for the GC/MS analysis was performed on a DuPont 950 instrument. Volatile products were collected in a Tenax containing tube which was attached to the GC inlet port, GC/MS was performed on a Hewlett Packard 5982A coupled to a 5934A data system. DSC was performed on a DuPont 1090 analyzer using a DuPont 910 DSC module. 

GC-Fourier transform infrared (GC-FI IR) spectroscopy is less frequently used than GC-MS, but involves a similar principle in which the outlet from the column is coupled to an infrared spectrophotometer. The technique currently suffers from a lack of library spectra, as the IR spectra taken in the vapour phase can be subtly different from condensed phase spectra or spectra collected using the well-established KBr disc method. 

---