Ultraviolet-Visible-Near Infrared spectroscopy

F.C. Jentoft, Ultraviolet-Visible-Near Infrared Spectroscopy in Catalysis Theory, Experiment, Analysis, and Application Under Reaction Conditions, Adv. CataL, 52, 129-211 (2009). 

UV-vis(-NIR) Ultraviolet-visible(-near-infrared) spectroscopy Electron and charge transfer transitions... 

Jentof FC (2009) Ultraviolet-visible-near infrared spectroscopy in catalysis theory, experiment, analysis and application under reaction conditions. In Gates BC, Kndzinger H (eds) Advances in catalysis, vol 52. Academic Press, Amsterdam... 

For small prisms, [/i = 10 nm) the absorption and scattering spectra present only two peaks these features could be attributed to the in-plane dipole resonance (longer wavelengths) and to the inplane quadrupole resonance [44]. By increasing the side of the triangle, a clear red-shift of these two peaks appears (see Fig. 3.8) and this is also confirmed experimentally by ultraviolet-visible-near-infrared spectroscopy measurements [44]. This effect can be understood by considering the fact that by enlarging the area of... 

Ultraviolet-Visible-Near Infrared (UV-vis-NIR) Spectroscopy in Catalysis... 

Volumes 50 and 51 of the Advances, published in 2006 and 2007, respectively, were the first of a set of three focused on the physical characterization of solid catalysts in the functioning state. This volume completes the set. The six chapters presented here are largely focused on the determination of structures and electronic properties of components and surfaces of solid catalysts. The first chapter is devoted to photoluminescense spectroscopy it is followed by chapters on Raman spectroscopy ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy X-ray photoelectron spectroscopy X-ray diffraction and X-ray absorption spectroscopy. 

Ultraviolet, visible, near-infrared, and mid-range infrared spectroscopies all work as per Beer s law. This has been proven during the past 100 or so years in several million assays. Therefore, distinguish between a case in which the procedure works even if a particular instrument does not and one in which the procedure or technique does not work. [The best hitters in baseball do not get a hit 70% of their times at bat, but there are no cries for bats to be abandoned because they don t work ]... 

Recently, ICH guidance Q6A has simplified the development of specifications in several ways, not the least of which is the clarification that impurities if already controlled in the API do not have to be controlled in the dosage form unless they are also degradants. For the release assay, this paves the way for simpler, but no less sophisticated methods that require minimal sample preparation. Thus, the future may bring a return to spectroscopic techniques such as ultraviolet/visible (LJV/vis) spectroscopy. There also may be increased use of other high-speed and high-precision techniques such as flow injection analysis (FIA) and near infrared (NIR) analysis. 

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... 

In this regard, various analytical methods have been developed and their potential for the VOO authentication has been evaluated. Thus, spectroscopic tools, such as FT-near-infrared spectroscopy, FT-Raman spectroscopy, fluorescence and ultraviolet-visible detectors, and chromatographic techniques have been widely used in the field of VOO authentication [43-48],... 

Quantitative analysis is well e.stablished not only in ultraviolet/visible and in near-infrared spectroscopy, but it is also very important in mid-infrared measurements. The general prerequisite for spectrometric quantitative analysis is defined as follows [35] information derived from the spectrum of a sample is related in mathematical terms... 

Raman spectroscopy has recently gained popularity for advanced chemical analysis of surfaces. In nanoscience, Raman spectroscopy is used to characterize surface properties of materials, measure temperature, and determine crystallinity. Raman spectroscopy is a spectroscopic technique used in material science to study vibrational and rotational frequencies in a system. The technique measures shifts in inelastic scattering, or Raman scattering, of light from a visible, near infrared or near ultraviolet light source and the shift in energy provides information about the material s surface characteristics. The Raman signal unit is a measurement of the ratio between the Stokes (down-shifted) intensity and anti-Stokes (up-shifted) intensity peaks. 

Among thm, techniques based on near infrared spectroscopy (MRS) have certainly become extremely important ones for practical reasons discussed in the following sections. Useful applications have also been developed for middle infrared (MIR), visible (VIS), and ultraviolet (UV) spectroscopic techniques. However, usually spectroscopic methods cannot be used as ad hoc monitoring techniques, so... 

Raman spectroscopy relies on inelastic (Raman) scattering of monochromatic light from a laser in the visible, near infrared, or near ultraviolet range. Raman spectroscopic techniques have historically failed to separate different black resins. SpectraCode [79]... 

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). 

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