Infrared continued spectroscopy

Eventually, rapid methods based on techniques such as near-infrared reflectance spectroscopy (NIRS) are expected to replace chemical methods for routine feed analysis, but bioavailability is expected to continue to be measured in animal studies. 

There are more techniques available on the market for the combustion exhaust composition measurement. For example, the Fourier transform infrared (FTIR) spectroscopy. Continuous emission monitoring system (CEMS) MultiGas 2030 provides real-time, simultaneous measurement of the concentrations of flue gas components ranging from water vapor, nitrogen oxides, sulfur oxides, ElCl, ammonia, H2SO4, and many other compounds. Many organic species can... 

Adamus et al. [26] studied copolymers with units of beta-butyrolactone (HB) and2-hydroxyhexanoic acid (2HHA) with ESI. The mixture of HB and 2HHA was stirred and heated at 70°C. The heating was continued until the racemic beta-butyrolactone was consumed, as determined by infrared (IR) spectroscopy (disappearance of beta-lactone carbonyl absorption band at 1815/cm).The copolymer yield was higher than 80%. The subsequent SEC analysis allowed to estabhsh that the polydispersity index is reasonably large ( I =1.6). 

Infrared (IR) spectroscopy has long been used to determine molecular structure and to identify unknown compounds. IR data have been used to obtain information about the chemical composition, configuration, and crystalienity of polymeric materials. Recently, IR spectroscopy has encountered competition from other techniques, such as NMR and x-ray diffraction. Nevertheless, IR spectroscopy s importance as an experimental technique continues largely because of the rapid development of Fourier transform infrared (FTIR) spectroscopy, which is sensitive to the detailed structure of a molecule. 

Near-infrared (NIR) spectroscopy has been found to be a useful technique to characterize raw materials and finished textile products, and NIR methods and techniques continue to find increasingly diverse and wide-ranging quantitative and qualitative applications in the textile industry. Quantitative analyses determine the amount (or quantity) of the property/species of interest in a substance or material. Qualitative analyses can be used to either identify a specific species or subsfance present in a material (i.e., coating on a fiber), the type of material itself (i.e., cotton, nylon, or polyester), or the quality of the material. NIR quantitative and qualitative methods allow the user to rapidly, accurately, and precisely monitor key chemical, physical, and morphological properties of textile fibers, yarns, fabrics, and chemical textile auxiliaries. Chemical properties are specific chemical species or groups present in the material (i.e., CH, OH, NH) that result in NIR spectral absorbencies at distinctive... 

Continuous wave (CW) lasers such as Ar and He-Ne are employed in conmionplace Raman spectrometers. However laser sources for Raman spectroscopy now extend from the edge of the vacuum UV to the near infrared. Lasers serve as an energetic source which at the same hme can be highly monochromatic, thus effectively supplying the single excitation frequency, v. The beams have a small diameter which may be... 

For the visible and near-ultraviolet portions of the spectmm, tunable dye lasers have commonly been used as the light source, although they are being replaced in many appHcation by tunable soHd-state lasers, eg, titanium-doped sapphire. Optical parametric oscillators are also developing as useful spectroscopic sources. In the infrared, tunable laser semiconductor diodes have been employed. The tunable diode lasers which contain lead salts have been employed for remote monitoring of poUutant species. Needs for infrared spectroscopy provide an impetus for continued development of tunable infrared lasers (see Infrared technology and RAMAN spectroscopy). 

Spectroscopy. Infrared spectroscopy (48) permits stmctural definition, eg, it resolves the 2,2 - from the 2,4 -methylene units in novolak resins. However, the broad bands and severely overlapping peaks present problems. For uncured resins, nmr rather than ir spectroscopy has become the technique of choice for microstmctural information. However, Fourier transform infrared (ftir) gives useful information on curing phenoHcs (49). Nevertheless, ir spectroscopy continues to be used as one of the detectors in the analysis of phenoHcs by gpc. 

Sohd-state multi-element detector arrays in the focal planes of simple grating monochromators can simultaneously monitor several absorption features. These devices were first used for uv—vis spectroscopy. Infrared coverage is limited (see Table 3), but research continues to extend the response to longer wavelengths. Less expensive nir array detectors have been appHed to on-line process instmmentation (125) (see Photodetectors). 

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