Near-infrared spectroscop applications

Multicomponent Spectral Analysis by Moving Window Partial Least-Squares Regression with Applications to Mid-Infrared and Near-Infrared Spectroscopic Data, Anal. Chem., 74 (2002) 3555. 

Sato, T. (1994) Application of principal-component analysis on near-infrared spectroscopic data of vegetable-oils for their classification. Journal of the American Oil Chemists Society, 71, 293-8. 

Pharmaceutical and medical applications of near-infrared spectroscope... 

With this rapid growth of near-infrared spectroscopic research in the health sciences, it is time for a text such as this. The authors have combined more than 35 years of industrial and university research experience in this volume. The pharmaceutical presentation is arranged in a logical progression theory, instrumentation, physical manipulation (blending, drying, and coating), analysis (both qualitative and quantitative), and finally, validation of the method. The varied mathematics used in NIR, called chemometrics, are only briefly mentioned. Detailed explanations and applications are covered in texts or chapters devoted to the subject [1-4]. 

H.Z. Zhang, T.C. Lee. Rapid near-infrared spectroscopic method for the determination of free fatty acid in fish and its application in fish quality assessment. J Agric Food Chem 45 3515-3521, 1997. 

Karl is regarded as the father of modern near-infrared spectroscopic analysis. He was a major force in the development of the near-infrared reflection technology for the simple, accurate, rapid, and inexpensive testing of many quality characteristics of food and grains. This technology has now been widely accepted and has revolutionized the way many chemical analyses are performed. As one can see in the applications chapters that follow, the near-IR approach to the determination of sample composition now permeates nearly every industry. 

Fourier transform near-infrared spectroscopy, using the C=CH band at 61S2cm for methacrylates, enabled the conversion to be followed in a single sample throughout the polymerization to high conversion. Parallel experiments were performed for near-infrared spectroscopic determination of monomer concentrations and for ESR measurements of radical concentrations. A further advantage of the near-IR method is its applicability to insoluble crosslinked systems. 

Miniaturized chemical analysis systems have been developed for most macroscopic counterparts (Dittrich et al. 2006). The availability of optical fibers, light sources, and detectors in the visible UV and near-infrared (NIR) wavelengths makes it possible to integrate spectroscopic measurements in microreactors (Lobbecke et al. 2005). Fourier transform infrared spectroscopy (FTIR) is an efficient, broadly applicable... 

Siesler HW, Ozaki Y, Kawata S, Heise HM. Near-Infrared Spectroscopy Principles, Instruments and Applications. Weinheim, Germany Wiley, 2002. Wetzel DL. Near Infrared reflectance analysis Sleeper among the spectroscopic techniques. Anal Chem 1983 55(12) 1165A-1175A. 

One indication of the developing interest in PATs in the pharmaceutical area is the number of book chapters and review articles in this field that have appeared in the last few years. Several chapters in The Handbook of Vibrational Spectroscopy3 are related to the use of various optical spectroscopies in pharmaceutical development and manufacturing. Warman and Hammond also cover spectroscopic techniques extensively in their chapter titled Process Analysis in the Pharmaceutical Industry in the text Pharmaceutical Analysis.4 Pharmaceutical applications are included in an exhaustive review of near-infrared (NIR) and mid-infrared (mid-IR) by Workman,5 as well as the periodic applications reviews of Process Analytical Chemistry and Pharmaceutical Science in the journal Analytical Chemistry. The Encyclopedia of Pharmaceutical Technology has several chapters on spectroscopic methods of analysis, with the chapters on Diffuse Reflectance and Near-Infrared Spectrometry particularly highlighting on-line applications. There are an ever-expanding number of recent reviews on pharmaceutical applications, and a few examples are cited for Raman,7 8 NIR,9-11 and mid-IR.12... 

Any practical clinical application of noninvasive near-infrared spectroscopy demands selective quantification of the targeted matrix component. For spectroscopic... 

The concept of the PCSA method is general and this method should be applicable to many types of multivariate calibration techniques. As near-infrared and other spectroscopic methods are developed further for noninvasive in vivo clinical measurements, it is critical to understand the chemical basis of measurement selectivity. Unfortunately, calibration models generated from multivariate statistics are typically accepted without further investigation. Application of the PCSA method can help to establish the chemical or spectroscopic basis of predicted concentrations. 

The first optical laser, the ruby laser, was built in 1960 by Theodore Maiman. Since that time lasers have had a profound impact on many areas of science and indeed on our everyday lives. The monochromaticity, coherence, high-intensity, and widely variable pulse-duration properties of lasers have led to dramatic improvements in optical measurements of all kinds and have proven especially valuable in spectroscopic studies in chemistry and physics. Because of their robustness and high power outputs, solid-state lasers are the workhorse devices in most of these applications, either as primary sources or, via nonlinear crystals or dye media, as frequency-shifted sources. In this experiment the 1064-mn near-infrared output from a solid-state Nd YAG laser will be frequency doubled to 532 nm to serve as a fast optical pump of a raby crystal. Ruby consists of a dilute solution of chromium 3 ions in a sapphire (AI2O3) lattice and is representative of many metal ion-doped solids that are useful as solid-state lasers, phosphors, and other luminescing materials. The radiative and nonradiative relaxation processes in such systems are important in determining their emission efficiencies, and these decay paths for the electronically excited Cr ion will be examined in this experiment. 

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... 

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