Correlation spectroscopy, near-infrared

Macromotecular Symposia Vol.119, July 1997, p.1-13 APPLICATIONS OF TWO-DIMENSIONAL CORRELATION SPECTROSCOPY IN DEPTHPROFILING PHOTOACOUSTIC SPECTROSCOPY, NEAR-INFRARED DYNAMIC RHEO-OPTICS, AND SPECTROSCOPIC IMAGING MICROSCOPY Noda I Story G M Dowrey A E Reeder R C ... 

I. Noda, G. M. Story, A. E. Dowrey, R. C. Reeder, C. Marcott. Applications of two-dimensional correlation spectroscopy in depth profiling photoacoustic spectroscopy, near-infrared dynamic rheooptics, and spectroscopic imaging microscopy. Makwmol Chem Macromol Symp 119 1,1997. 

L. Silveira Jr., S. Sathaiah, R. A. Zangaro, M. T. Pacheco, M. C. Chavantes and C. A. Pasqualucci, Correlation between near-infrared Raman spectroscopy and the histological analysis of atherosclerosis in human coronary arteries. Lasers Surg. Med., 2002, 30(4), 290-297. 

Characterization. In many cases, ftir is a timely and cost-effective method to identify and quantify certain functionaHties in a resin molecule. Based on developed correlations, ftir is routinely used as an efficient method for the analysis of resin aromaticity, olefinic content, and other key functional properties. Near infrared spectroscopy is also quickly becoming a useful tool for on-line process and property control. 

V. Toronov, A. Webb, J. H. Choi, M. Wolf, L. Safonova, U. Wolf, and E. Grat-ton. Study of local cerebral hemodynamics by frequency-domain near-infrared spectroscopy and correlation with simultaneously acquired functional magnetic resonance imaging. Optics Express, 9 417-427, 2001. 

Near Infrared Reflectance Analysis (NIRA) is in use at over 5000 sites for the analysis of multiple constituents in food and other products. The technology is based upon correlation transform spectroscopy, which combines NIR spectrophotometry and computerized analysis of a "learning set" of samples to obtain calibrations without the need for detailed spectroscopic knowledge of factors being analyzed. The computer can obtain spectral characteristics of the analyte (based upon a correlation with data from an accepted reference analysis) without separation of the sample s constituents. 

In other cases, a baseline corrected peak height for a particular absorber may be employed as a term in the equation. In such a case, the wavelength difference on either side of a peak maximum will affect the contribution of that complex term. That increment or gap, in fact, under such circumstances becomes a part of the calibration. It is as important a contribution to the calibration as the coefficients on the wavelength terms. In this correlation spectroscopy, classical band assignments are not always possible. Little specific near-infrared literature exists in advance of most applications and it is not always possible to predict which wavelengths will produce the best linearity and the best sensitivity for a given analytical problem. In the empirical approach a variety of statistical treatments have been attempted. By far the most... 

In the current study, we tested the applicability of near infrared spectroscopy coupled with correlation analysis to quantitation of the dependence of montmorillonite spectra on two of the structural features known to be of importance in clay surface chemistry -hydration and exchangeable iron. These clays were... 

COYNE ETAL. Near-Infrared Correlation Spectroscopy... 

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. 

Bilia et al. reported the efficiency of two-dimensional homonuclear H- H correlated spectroscopy and two-dimensional reverse heteronuclear shift correlation spectroscopy in evaluating the composition of phloroglucinols, flavonols and naphthodianthrones in a dried extract of St John s wort. They successfully assigned carbon resonances for these three classes of compounds and also identified shikimic and chlorogenic acids, sucrose, lipid, polyphenols and traces of solvent (methanol) during the extraction process. This rapid technique is an alternative to HPLC, TLC or capillary GC for the analysis of St John s wort preparations. Another report utilized near-infrared reflectance spectroscopy (NIRS) for the... 

FE Barton II and DS Himmelsbach. Two-Dimensional Vibrational Spectroscopy 11 Correlation of the Absorptions of Lignins in the Mid- and Near-Infrared. Appl. Spectrosc. 47 1920-1925, 1993. 

FE Barton 11, DS Himmelsbach, and DD Archibald. Two-Dimensional Vibration Spectroscopy. V. Correlation of Mid- and Near Infrared of Hard Red Winter and Spring Cheats. Near Infrared Spectrosc. 4 139-152, 1996. 

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... 

Schroeder SLM, Moggridge GD, Lambert RM, Rayment T (1997) Self-absorption effects in grazing-incidence total electron-yield XAS. J Phys IV 7 91-96 Segtnan VH, Sasic S, Isaksson T, Ozaki Y (2001) Studies on the Structure of Water Using Two-Dimensional Near-Infrared Correlation Spectroscopy and Principal Component Analysis. Anal Chem 73 3153-3161... 

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