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Infrared spectroscopy analysis using

Terahertz, or far infrared spectroscopy, covers the frequency range from 0.1 to lOTHz (300 to 3cm ) where torsional modes and lattice vibrations of molecules are detected. It is increasing in use in many application areas, including analysis of crystalline materials. Several dedicated conunercial instruments are available which use pulsed terahertz radiation which results in better signal to noise than those using blackbody sources for radiation (and associated with the terminology far infrared spectroscopy). Work using extended optics of FTIR instrumentation as weU as continuous-wave source THz has also been recently reported. ... [Pg.531]

Infrared Spectroscopy. The use of IR (9.10.11.12) and FTIR (3.4) for coal mineralogy has been reported. Painter and coworkers (3) demonstrated that FTIR can provide a virtually complete analysis. Painter, Brown and Elliott (4), and others (9.10.11) discuss sample preparation, reference minerals, and data analysis. The advantages of IR are 1) high sensitivity to molecular structure, 2) unequivocal identification of a number of minerals, 3) small sample size (a few milligrams), and 4) rapid analysis time (once LTA is available). Disadvantages include 1) reliance on reference minerals, 2) requires careful attention to sample preparation, and 3) limited selectivity (discrimination among similar minerals). [Pg.48]

Corrosivity of used oils. The classical determination of TBN and TAN involves a titrimetric procedure, whereby the oil sample is dissolved in a particular solvent system and neutralized by strong acid or strong base (ASTM D664 or 2896), equivalent to (IP 171 or 276). TBN and TAN values do not correlate with corrosivity and the titrimetric analysis has a very limited ability to differentiate between acids of varying strengths. A quantitative differential infrared spectroscopy technique used to monitor the neutralization reaction is more meaningful, since the technique applies to reactions in hydrocarbon solvents. The classical reaction between corrosive acids and hard-core RMs results in formation of the metal salt of the acid and carbonic acid ... [Pg.90]

FIGURE 31.18 Near Infrared Spectroscopy analysis provides clear delineation of the hydration profiles of emollient BW relative to water washing or lotion use. NIR shows good correlation with the visible appearance and clearer product differentiation compared to skicon. [Pg.425]

Conversion of the as-deposited film into the crystalline state has been carried out by a variety of methods. The most typical approach is a two-step heat treatment process involving separate low-temperature pyrolysis ( 300 to 350°C) and high-temperature ( 550 to 750°C) crystallization anneals. The times and temperatures utilized depend upon precursor chemistry, film composition, and layer thickness. At the laboratory scale, the pyrolysis step is most often carried out by simply placing the film on a hot plate that has been preset to the desired temperature. Nearly always, pyrolysis conditions are chosen based on the thermal decomposition behavior of powders derived from the same solution chemistry. Thermal gravimetric analysis (TGA) is normally employed for these studies, and while this approach seems less than ideal, it has proved reasonably effective. A few investigators have studied organic pyrolysis in thin films by Fourier transform infrared spectroscopy (FTIR) using reflectance techniques. - This approach allows for an in situ determination of film pyrolysis behavior. [Pg.539]

Fourier transform-infrared spectroscopy analysis of collected peaks used to confirm analyte identification. [Pg.1094]

Gas chromatography/infrared spectroscopy analysis was also used under differing operating parameters to aid in compound identification. [Pg.1097]

The tables that follow contain information on the Chemical Warfare Agents Simulants (Table 2), degradation products of actual chemical agents (Table 3) and on the Toxic Industrial Compounds (Table 4) studied. Raman Spectroscopy and Fourier Transform Infrared Spectroscopy were used for the vibrational analysis. Spectra were compared to... [Pg.203]

Infrared spectroscopy is used for the analysis of almost all the fractions and products of crude oil. However, in the last century, a very interesting purpose of the infrared spectroscopy has been developed. It is the dynamic monitoring of the changes in the structure of lubricating oils as it undergoes degradation. Many processes such as oxidation or polycondensation in oils can be studied by infrared spectroscopy. [Pg.126]

Spectroscopic methods are also commonly used for the analysis of surfactants. Among these methods ultraviolet/visible spectrophotometry and infrared/near-infrared spectroscopy are used for the measurement of surfactant concentration, while such techniques as nuclear magnetic resonance (NMR) and mass-spectroscopy (MS) are extensively used for... [Pg.151]

In the characterization of building and construction materials, the most frequently analytical tool performed have been X-ray diffraction but also, thermal analysis and microscopic techniques. Nowadays, infrared and other spectroscopic techniques have become as a useful, non-destructive and easy technique to study the phase composition of initial but also the evolved materials due to their exposure to the climatic conditions. Moreover, by using this tool is possible the detection of crystalline but also the amorphous phases very frequently developed on certain cementitious materials, mainly at early ages. The infrared spectroscopy is used both to gather information about the structure of compoimds and as analytical tool to assess in qualitative and quantitative analysis of mixtures. [Pg.369]

Infrared spectroscopy is used in the paint industry for quality control, product improvement and failure analysis, and for forensic identification purposes [8, 18-21], Paints are mainly comprised of polymeric binders and pigments in a dispersive medium. The binders are commonly alkyds (oil-modified polyesters), acrylics and vinyl polymers. Titanium oxide is the most commonly used pigment, while water or organic solvents are used as the medium. Paints may also contain other additives such as fillers (e.g. calcium carbonate) and stabilizers (e.g. lead oxide). [Pg.180]

Tremendous advances have been made recently in the use of near-infrared spectroscopy for the analysis of pharmaceutical dosage forms. Just 25 years ago, near-infrared spectroscopy was used in a way that offered relatively few advantages over other analytical methods for the analysis of dosage... [Pg.87]

J. Workman and L. Weyer, Qualitative Near Infrared Reflectance Analysis Using Mahalanobis Distances, Practical Guide to Interpretive Near-Infrared Spectroscopy, CRC Press, Boca Raton, FL, 2007. [Pg.89]

A second example involves reflectance infrared spectroscopic structural analysis of polydimethylsiloxane at the air-water interface. Surface pressure versus surface area or surface concentration isotherms of polydimethylsiloxane on water have been studied since 1947 at least (223). Upon compression, the isotherm begins at zero surface pressure at surface concentrations significantly below 0.75 mg/m. Around f 1 0.75 mg/m, the surface pressure tt jumps substantially to about 9 mN/m, where it exhibits a plateau until about T2 1.6 mg/m, where a small Tt jump occurs followed by a smaller rise (Fig. 31). Structural features associated with the various transitions have often been debated. Particular controversy is associated with the ix plateau aroimd 9 mN/m between Fi and T2 (224,225). In conjimction with other techniques, such as epifluorescence microscopy, external reflectance infrared spectroscopy was used to study microstructural features (coexistence of two phases) of polydimethylsiloxane CH3—[Si(CH3)2—Oln—SKCHala, spread at the air-water interface in the vicinity of the n plateau at 9 mN/m (226). A broad band containing several components is foimd in the 1000-1100 cm ... [Pg.8818]

This cited reference documents numerous compounds in these and other general compound classes, fyourier transform-infrared spectroscopy analysis of collected peaks used to confirm analyte identification. [Pg.1022]

In 1978, Audette and Percy introduced the idea of first examining a paint chip by infrared spectroscopy (IR) using a KBr pellet and then pyrolyzing the same pellet for gas chromatographic analysis (249). This method offers high discriminative power with (he use of two distinctly different techniques and a very small amount of sample (3-5 p,g). [Pg.951]

Pereira L, Pereira R, Oliveira CS, Alves MM (2013) UV/Ti02 photocatalytic degradation of xanthene dyes. Photochem Photobiol, 2013,89 33-50. doi 10.1111/j.l751-1097.2012.01208.x Perez F (2001) Spectrophotometric study of industrial effluents - application in parameters estimation. PhD thesis, Universite d Aix-Marseille II Pielesz A (1999) The process of the reduction of azo dyes used in dyeing textiles on the basis of infrared spectroscopy analysis. J Mol Struct 337-344. http //www.doi.oig/10.1016/ S0022-2860(99)00176-3... [Pg.343]

The successful modification has been confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy analysis. Additive manufactured PCL/silanized tricalcium phosphate scaffolds have been fabricated using a screw extrusion system. Testing mechanical properties have demonstrated that both... [Pg.146]

Infrared analysis can be used for almost any type of sample as long as the material is composed of or contains compounds (rather than pure elements). It is a nondestructive type of analysis (the sample can normally be recovered for other use), and is useful for microsamples (down to the sub-microgram range). In its earlier years, infrared spectroscopy was used primarily for organic materials, but, especially since the advent of long-wavelength instrumentation, it has been found to be equally useful for the analysis of inorganic compounds. [Pg.1]

Analysis of infrared spectra can teU you what molecules are present in a sample and at what concentrations this is why infrared spectroscopy is useful. There are several types of infrared spectrometers in the world, but the most widely used ones are FTlRs, which is the focus here. This book will teach you how FTlRs work, how to use them to obtain the best spectra, how to use FTIR software to assist in data analysis, how to properly prepare samples for FTIR analysis, how to quantify concentrations in samples using FTIR spectra, and infrared microscopy. In essence, we will be studying everything involved in obtaining a good infrared spectrum. For information on how to interpret an infrared spectrum to determine the structures of molecules present in a sample please consult my book on infrared spectral interpretation [1]. [Pg.1]

We measure infrared spectra to answer questions about samples. One question we commonly try to answer is, What molecules are present in this sample , otherwise called unknown analysis. The peak positions in an infrared spectrum correlate with molecular structure, which is part of why infrared spectroscopy is useful. Over the last 100-plus years a great number of infrared spectra have been measured, and the peak positions of known molecules derived from these spectra can be used to identify the molecules in an unknown sample [1]. [Pg.8]

Fourier Transform Infrared Spectroscopy Analysis A ThermoNicolet Nexus 470 spectrometer was used for FTIR analysis to detect the presence of functional groups in the membranes. Thin membrane samples were attached to a polyethylene substrate FTIR card from Thermo Electron Cotp. and analyzed at ambient temperature. All spectra were obtained from 100 scans at 4.0 cm resolution with spectra ranging from 400 to 4000 cm. ... [Pg.196]

Fast Fourier Transformation is widely used in many fields of science, among them chemoractrics. The Fast Fourier Transformation (FFT) algorithm transforms the data from the "wavelength" domain into the "frequency" domain. The method is almost compulsorily used in spectral analysis, e, g., when near-infrared spectroscopy data arc employed as independent variables. Next, the spectral model is built between the responses and the Fourier coefficients of the transformation, which substitute the original Y-matrix. [Pg.216]


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