Fourier transform infrared spectrophotometry

Residues are determined in the purified extracts by chromatographic or immunochemical techniques. In the chromatographic systems, thin-layer chromatography (TEC), liquid chromatography (LC), and GC, the analytes are separated on plates or columns and determined by colorimetry, by spectrophotometry (ultraviolet (UV), infrared (IR, Fourier transform infrared (FTIR)), by fluorescence, by selective detectors (in GC analysis ECD, flame photometric (FPD), nitrogen/phosphorus (NPD, TSD), etc.), or by MS. Separations may also be achieved by... 

S. Modeling color and chemical changes on normal and red heart beech wood by reflectance spectrophotometry, Fourier Transform Infrared spectroscopy and h5fperspectral imaging. Polym. Degrad. Stab. 113, 10-21 (2015)... 

Several direct spectrophotometric methods are used for sulfur dioxide measurement, including nondispersive infrared absorption, Fourier transform infrared analysis (FTIR), ultraviolet absorption, molecular resonance fluorescence, and second-derivative spectrophotometry. The principles of these methods are the same for any gas measured. 

Always based on the use of IR spectrophotometry, a novel attenuated total reflection-Fourier-transform infrared (ATR-FTIR) sensor [42] was proposed for the on-line monitoring of a dechlorination process. Organohalogenated compounds such as trichloroethylene (TCE), tetrachloroethylene (PCE) and carbon tetrachloride (CT) were detected with a limit of a few milligrams per litre, after extraction on the ATR internal-reflection element coated with a hydro-phobic polymer. As for all IR techniques, partial least squares (PLS) calibration models are needed. As previously, this system is promising for bioprocess control and optimization. 

FTNIR (Fourier transform near-infrared spectrophotometry), 663 FuUerene adducts, regioselective... 

Mirabella, F. M., Jr. (1987) Applications of microscopic Fourier transform infrared spectrophotometry sampling techniques for the analysis of polymer systems. In The Design, Sample Handling and Applications of Infrared Microscopes (P. B. Rousch, ed.), American Society for Testing and Materials, Philadelphia, PA, pp. 74—83. 

Absorption spectrophotometry (UV-Vis) Fourier transform infrared, resonance Raman and fluorescence spectroscopy X-ray diffraction... 

Fourier transform infrared spectrophotometry is used widely in the semiconductor industry for the routine determination of the interstitial oxygen content of production silicon wafers. However, the lack of interlaboratory reproducibility in this method has forced the use of ad-hoc calibration methods. The sources of this lack of reproducibility are just beginning to be understood. As investigation of this problem continues and wider acceptance is gained for improved experimental and analytical techniques, a greater degree of reproducibility should be achieved. Furthermore, new standard test methods and standard reference materials being developed by the ASTM (71 ),... 

Cordon, B.M., W.M. Coleman III, J.F. Elder Jr, J.A. Ciles, D.S. Moore, C.E. Rix, M.S. Uhrig, and E.L. White Analysis of flue-cured tobacco essential oil using multidimensional gas chromatography mass spectrometry and matrix isolation Fourier transform infrared spectrophotometry 41st Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 41, Paper No. 7, 1987, p. 15. 

Infrared spectrophotometry is a familiar established analytical technique which provides identification of compounds by fingerprint spectra, of which a vast library is available. Both liquid and gaseous samples may be easily analysed and therefore modifications of established sample handling techniques have enabled both GC and HPLC instruments to be readily interfaced. Ideally, scan times of less than 1 s are required to be able to record each peak and peak shoulders. Instrument sensitivity is sufficient so that on the fly recording of spectra can be obtained from GC and HPLC eluants which contain nanograms of sample per ml mobile phase, for example, 10 ng sample in 100 pi GC-IR sample cell. Fourier transform infrared (FTIR) instruments are able to meet these criteria but until recently the instrumentation and computer system have been too expensive for routine use. The new generation of... 

Chemical analysis of hazardous substances in air, water, soil, sediment, or solid waste can best be performed by instrumental techniques involving gas chromatography (GC), high-performance liquid chromatography (HPLC), GC/mass spectrometry (MS), Fourier transform infrared spectroscopy (FTIR), and atomic absorption spectrophotometry (AA) (for the metals). GC techniques using a flame ionization detector (FID) or electron-capture detector (BCD) are widely used. Other detectors can be used for specific analyses. However, for unknown substances, identification by GC is extremely difficult. The number of pollutants listed by the U.S. Environmental Protection Agency (EPA) are only in the hundreds — in comparison with the thousands of harmful... 

DSC and Fourier-transform infrared spectrophotometry (FTIR) are used to detect possible changes in the physical-chemical properties of the active ingredient and/or carrier, and possible interactions between the components used in the formulations, respectively. 

Fourier Transform Infrared Spectrophotometry. Thin films of the polymers were prepared from 5% by weight solutions of the polymers in methylene chloride via a doctor blade. A Nicolet Magna-FTIR Spectrometer 550 was used to record the transmission spectra of thin films. 

Fourier transform infrared spectrophotometry (FTIR) spectra of the neutral pol5mier PEDOT indicates a regular structure formed via a-a coupling of thiophene rings. The polymer shows two absorption bands at 341 nm and 413-419 nm in an N-methyl-2-p5n-rolidone (NMP) solution in the ultraviolet-visible (UV-Vis) luminescence with peak at ca. 552 nm. 

Products were characterized by Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR), ultraviolet visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), and broadband dielectric/impedance spectroscopy (BDS). New absorption bands were observed corresponding to the conjugated pol5mieric units by FTIR-ATR and UV-Vis spectrophotometric analysis. The influence of concentration of PEDOT-PSS and PEDOT on the composite electrospun nanofibers was studied by EIS. Morphologies of electrospun nanofibers were also investigated by SEM. 

The chemical polymerization of Py by CAN in PU solutions leads to the formation of PU/PPy composites. The composites were characterized by Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR], dynamic mechanical analysis (DMA], thermal gravimetric analysis (TGA], differential scanning calorimetry (DSC], X-ray photoelectron spectroscopy (XPS], and SEM measurements. The absorbances of the disordered H-bonded urethane carbonyl decrease with increasing Py concentration. The fraction of the hydrogen-bonded carbonyls is increased and the melting point increases with the increase of PPy content. These indicate the incorporation of PPy into PU may cause the complex due to the intermolecular interaction between the PPy and PU. SEM images of composite nanofibers show good distribution of the second component and the composite solution is proper to form conductive composite nanofibers. 

See also Asbestos. Color Measurement. Forensic Sciences Thin-Layer Chromatography. Gas Chromatography Pyrolysis Mass Spectrometry Fourier Transform Infrared Spectroscopy. Microscopy Applications Forensic. Spectrophotometry Diode Array. Textiles Natural Synthetic. X-Ray Absorption and Diffraction X-Ray Diffraction - Powder. X-Ray Fluorescence and Emission X-Ray Fluorescence Theory Energy Dispersive X-Ray Fluorescence Total Reflection X-Ray Fluorescence. 

Infrared (IR) spectrophotometry and gas chromatography-mass spectrometry (GC-MS) are commonly utilized to confirm the presence of heroin. Both IR and MS of heroin are unique and are easily distinguishable from other related compounds, thus providing a high degree of confidence in the identification process. The Fourier transform (FT) IR and MS spectra of heroin are shown in Figures 3B and 3C. The major IR absorption peaks for heroin hydrochloride, prepared in potassium bromide, are 1753, 1732, 1365, and 1230 cmT. The primary spectral features of heroin by electron-impact MS are ions at miz 369, 327, 310, and 268. 

Infrared spectrophotometry of ozone based on the principal absorption band near 9.5 pm is relatively free from interference by the bands of other atmospheric constituents. However, a long optical path is necessary for detection of atmospheric ozone. A White cell (multiple reflection cell, 10-1000 m path) combined with a Fourier-transform infrared (FTIR) spectrometer (spectral resolution of lcm or better) with a HgCdTe detector is often used in multi-component air-monitoring and smog chamber experiments. 

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