Near-infrared spectroscopy absorptions

Wang C, Mohney B K, Williams R, Hupp J T and Walker G C 1998 Solvent control of vibronic coupling upon intervalence charge transfer excitation of (NC)gFeCNRu(NH3)g- as revealed by resonance Raman and near-infrared absorption spectroscopies J. Am. Chem. Soc. 120 5848-9... 

Direct methods are based on an intrinsic property of the glucose molecule and the measurement of this property. The best example of a direct measurement is vibrational spectroscopy as implemented by near-infrared absorption spectroscopy or Raman scattering spectroscopy. A summary of the major methods is provided in Section 12.5. 

For brevity, results from selected in vitro and in vivo studies employing either near-infrared absorption spectroscopy or Raman spectroscopy, the most commonly used techniques, are documented in Tables 12.1 and 12.2. In these tables, error estimates are reported with either CV or P in parentheses, indicating cross-validated or predicted results, respectively. For an explanation of these terms, please refer to Section 12.4. 

Pendleton Y. J., Sandford S., AUamandola L., Tielens A. G. G. M., and Sellgren K. (1994) Near infrared absorption spectroscopy of interstellar hydrocarbon grains. Astrophys. J. 437, 683-696. 

W. F. Schrader, Non-Invasive Anterior Chamber Glucose Monitoring by Near-Infrared Absorption Spectroscopy, an Alternative to Blood-Glucose Monitoring in Diabetic Patients Proc. 96th DOG Annual Meeting, 1998. 

Near-infrared absorption spectroscopy is increasingly used in agriculture, food science, medicine, fife sciences, pharmaceuticals, textiles, general chemicals, polymers, process monitoring, food quality control and in clinical in vivo measurements [215, 216]. The increase in popularity is largely due to the availability of miniaturised NIR-spectrometers by a variety of vendors (e.g. Ocean Optics Inc.). The most promising applications of NIR-absorbance spectroscopy clearly lie in process control, because of the relatively low complexity of the sample in chemical and biochemical processes, e.g. compared to biological tissues. Also in food quality control... 

Takeuchi, M., Martra, G., Coluccia, S., and Anpo, M. Investigations of the structure of H20 clusters adsorbed on Ti02 surfaces by near-infrared absorption spectroscopy. The-Joumalof PhysicalChemisttyB, 109(15), 7387-7391 (2005). 

N. Oi and E. Inaba, Analyses of Drugs and Chemicals by Infrared Absorption Spectroscopy. 8. Determination of Allylisopropylacetuieide and Phenacetin in Pharmaceutical Preparations by Near Infrared Absorption Spectroscopy, Yakugaku Zasshi, 87,213 (1967). 

Oi, N. and Inaba, E., Analyses of drngs and chemicals by infrared absorption spectroscopy. 8. Determination of aUyUsopropylacetnreide and phenacetin in pharmacentical preparations by near-infrared absorption spectroscopy, Yakugaku Zasshi, 87(3), 213-215, 1967. 

A nano-light-source generated on the metallic nano-tip induces a variety of optical phenomena in a nano-volume. Hence, nano-analysis, nano-identification and nanoimaging are achieved by combining the near-field technique with many kinds of spectroscopy. The use of a metallic nano-tip applied to nanoscale spectroscopy, for example, Raman spectroscopy [9], two-photon fluorescence spectroscopy [13] and infrared absorption spectroscopy [14], was reported in 1999. We have incorporated Raman spectroscopy with tip-enhanced near-field microscopy for the direct observation of molecules. In this section, we will give a brief introduction to Raman spectroscopy and demonstrate our experimental nano-Raman spectroscopy and imaging results. Furthermore, we will describe the improvement of spatial resolution... 

In contrast to highly stable and prolific fullerene anionic species, fullerene cations are rare. The first fullerene cation was prepared in 1996 by Reed and co-workers500 by single-electron oxidation of C76 to form radical cation C76 + isolated in solid form as the CBnH6Br6 salt [Eq. (3.56)]. The cation was identified in solution by a characteristic visible-near-infrared absorption (Amax = 780 nm), FT-IR and EPR spectroscopy. C60 + was generated in an analogous way later.501 Reed et al.501 also succeded in... 

Bokobza, L. (2002). Origin of near-infrared absorption bands. In Near-Infrared Spectroscopy Principles, Instruments, Applications, Siesler, H. W., Ozaki, Y., Kawata, S., and Heise, H. M., eds., Wiley-VCH, Weinheim, Germany, pp. 11-39. 

Individual near-infrared absorption bands have absorptivities on the order of 10 1 Al /mm/mM for peak absorption bands in aqueous matrices.30 Such low absorptivities limit detection to the major components within skin tissue. As a general rule of thumb, substances must be present at concentrations above 1 mM to be quantified by near-infrared spectroscopy. Although such low absorptivities greatly restrict the number of possible analytes one can measure in clinical samples, the inability to measure chemicals present below millimolar concentrations enhances selectivity by rendering measurements insensitive to many different types of endogenous molecules. Only the major chemical components of these biological samples must be considered for selectivity purposes. 

The Visible and Near Infrared Absorption Spectra of Some Trivalent Actinide and Lanthanide Elements in DCIO4 and in Molten Salts, W.T. Camall and P.R. Fields, Developments in Applied Spectroscopy 1, 233-247 (1962). 

Vibrational Spectroscopy [Infrared (mid-IR, NIR), Raman]. In contrast to X-ray powder diffraction, which probes the orderly arrangement of molecules in the crystal lattice, vibration spectroscopy probes differences in the influence of the solid state on the molecular spectroscopy. As a result, there is often a severe overlap of the majority of the spectra for different forms of the pharmaceutical. Sometimes complete resolution of the vibrational modes of a particular functional group suffices to differentiate the solid-state form and allows direct quantification. In other instances, particularly with near-infrared (NIR) spectroscopy, the overlap of spectral features results in the need to rely on more sophisticated approaches for quantification. Of the spectroscopic methods which have been shown to be useful for quantitative analysis, vibrational (mid-IR absorption, Raman scattering, and NIR) spectroscopy is perhaps the most amenable to routine, on-line, off-line, and quality-control quantitation. 

Near-infrared absorption is therefore essentially due to combination and overtone modes of higher energy fundamentals, such as C-H, N-H, and O-H stretches, which appear as lower overtones and lower order combination modes. Since the NIR absorption of polyatomic molecules thus mainly reflects vibrational contributions from very few functional groups, NIR spectroscopy is less suitable for detailed qualitative analysis than IR, which shows all (active) fundamentals and the overtones and combination modes of low-energy vibrations. On the other hand, since the vibrational intensities of near-infrared bands are considerably lower than those of corresponding infrared bands, optical layers of reasonable size (millimeters, centimeters) may be transmitted in the NIR, even in the case of liquid samples, compared to the layers of pm size which are detected in the infrared. This has important consequences for the direct quantitative study of chemical reactions, chemical equilibria, and phase equilibria via NIR spectroscopy. 

In case (iii), which is most germane to this review, co-deposition and annealing enable binary complexes to be prepared, while careful infrared-spectroscopic studies, including isotopic substitutions, allow structures and bonding propensities to be determined. Matrix isolation with infrared absorption spectroscopy as the main diagnostic is a very general technique that can be applied to studying the photochemistry of many weakly bonded complexes of the kind described in this review. Its wide applicability derives from the fact that nearly all molecules of interest display IR absorptions, and... 

In this manuscript, the third factor was studied by sulfur K-edge X-ray absorption near-edge structure (XANES). Infrared absorption spectroscopy is often used to monitor the adsorbed/intermediate species on the surface. However, by infrared absorption, the atoms dissociated from reactant molecules that are buried into the catalysts are often inaccessible, e.g. sulfur atom of SO dissociated and reacted to form the RuS phase. The major objective of this paper is to monitor both adsorbed and buried sulfur atoms by S K-edge XANES in the preparation process of supported ruthenium catalysts. 

Near-infrared reflectance spectroscopy (NIRS) has been used in food industries for the determination of water, proteins, and oil content in food grains and other commodities (Williams and Norris, 2001). NIRS involves measurement of absorption spectra of a test material in the infrared region of 700 2500 nm. Compositional changes in the commodity are then correlated... 

While the majority of the studies of carotenoid radicals have been based on monitoring the strong near infrared absorption bands, other techniques, including time resolved resonance Raman spectroscopy (Jeevarajan et al., 1996), FTIR spectroscopy (Noguchi et al, 1994), EPR (Grant et al., 1988), ENDOR (Piekarasady et al., 1995), and cyclic voltametry (Grant et al, 1988) have also been used. 

Berg, J. I. "Near Infrared Absorption Coefficient of Molten Glass by Emission Spectroscopy." International Journal of Thermophysics 2, no. 4 (1981) 381-94. 

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