Fourier transform infrared spectrometer FT-IR

A Fourier transform infrared spectrometer (FT-IR) uses an interferometer,... 

A variety of analytical methods has been used for determining trace concentrations of PAHs in environmental samples (Table 6-2). These include GC with various detectors, HPLC with various detectors, and TLC with fluorimetric detectors. Various detection devices used for GC quantification include FID, MS, Fourier transform infrared spectrometer (FT-IR), laser induced molecular fluorescence detector (LIMF), diode array detector (DAD), and gas phase fluorescence detector (GPFDA). GC/MS and HPLC with UV or spectrofluorimetric detectors are perhaps the most prevalent analytical methods for determining concentrations of PAHs in environmental samples. 

A variation on the GC-MS technique includes coupling a Fourier transform infrared spectrometer (FT-IR) to a gas chromatograph. The substances that elute from the gas chromatograph are detected by determining their infrared spectra rather than their mass spectra. A new technique that also resembles GC-MS is high-performance liquid chromatography-mass spectrometry (HPLC-MS). An HPLC instrument is coupled through a special interface to a mass spectrometer. The substances that elute from the HPLC column are detected by the mass spectrometer, and their mass spectra can be displayed, analyzed, and compared with standard spectra found in the computer library built into the instrument. 

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... 

Fourier Transform Infrared Spectroscopy (FT-IR) measurements were made using a Nicolet Instruments 740 FT-IR spectrometer. A horizontal attenuated toted reflectance cell equipped with a 45° zinc-selenide crystal trough wets used. Spectra of neat solutions were obtained by co-addition of 256 scans at 4 cm- resolution. 

The modern spectrometers [7] came with the development of the high p>erformance Fourier Transform Infrared Spectroscopy (FT-IR) with the application of a Michelson Interferometer [10]. Both IR spectrometers classical and modern give the same information the main difference is the use of Michelson interferometer, which allows all the frequencies to reach... 

Fourier transform infrared spectroscopy (FT-IR) analysis of dried and annealed powders were carried out in an Impact 400, Nicolet spectrometer in the wavenumber range 400-4000 cmi at resolution of 4 cmi for studying the chemical groups. For this analysis, KBr pellets were pressed to hold the samples to be analyzed. 

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. 

Vibrational spectroscopy [3, 4] The infrared absorption spectrum of zaleplon, obtained in KBr disk is shown in Fig. 8.5. The spectrum was recorded on Jasco FT/IR 460 plus Fourier transform infrared spectrometer model. 

ECD = electron capture detector FID = flame ionization detector FT-IR = Fourier transform-infrared spectrometer GC = gas chromatography MS = mass spectrometry... 

The basic component of most Fourier Transform Infrared spectrometers is the Michel son interferometer. This is not the only interferometer used in FT-IR, but it is employed more often than other designs. A treatment of many other interferometer designs is available. The Michel son interferometer in a Fourier Transform Infrared spectrometer replaces the monochromator in a dispersive instrument, although the functions cannot be correlated. A monochomator divides a continuous bandwidth into its component frequencies, whereas an interferometer produces interference patterns of the bandwidth in a precise and regulated manner. It should be noted that this type of interferometer is not restricted to the infrared region and its use can be extended to the visible and millimeter regions of the electromagnetic spectrum. 

The function of the interferometer in a Fourier transform infrared spectrometer has been presented. An FT-IR spectrometer optical layout is now described and information is provided for each element of a typical spectrometer design. A schematic of a typical FT-IR optical design is given in Figure 6. 

Transmission FT-IR spectra were acquired with a Nico-let 5700 Fourier Transform Infrared spectrometer (Thermo Electron Corporation, Madison, WI, USA). The experimental conditions are listed in Table 1. Sampling was performed by placing one drop of solution onto a KBr pellet. The crystalline, purified TPPT was ground with dried KBr and pressed into a pellet. 

FT-IR spectra were taken on a Nicolet AVATAR 360 Fourier transform infrared spectrometer, which covered from 4000 to 400 cm, to characterize the surface structure of Cu nanoparticles. The prepared Cu nanoparticles were mixed with KBr powder and pressed into a pellet for measurement. Background correction was made using a reference blank KBr pellet. 

NMR spectra were recorded in deuterated chloroform or dimethyl for-mamide (DMF). FT-IR and UV spectra were recorded on a BioRad FTS-40 Fourier-Transform Infrared Spectrometer and a Hewlett Packard UV-visible spectrometer. 

Even though the number of the normal vibrations in a molecule is 3N-6, where N is the number of atoms in a molecule, the nucleic acids give no more than 50 well-defined absorption bands in the mid-infrared region 400-4000 cm . Vibrational spectroscopy is sensitive to conformational changes in biopolymers brought about by metal ions and it can be used to obtain information about the structure in both the solid and solution states. The spectra obtained with a Fourier transform infrared spectrometer are studied with differential techniques and the absorption of the H2O can be digitally subtracted from the solution spectra. Infrared spectra of aqueous solutions can be examined now with FT-IR techniques as opposed to the old prism and grating instruments. The spectra obtained with an FT-IR are handled with differential techniques and the data are treated with a computer. 

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