Near infrared, NIR

Sucrose quantitation has also been performed by colorimetric methods. However, in recent years, automated enzymatic analyzers and instmmental methods (eg, ion chromatography and hplc) have become increasingly popular, as they provide greater sensitivity and accuracy. Near infrared (nir) spectroscopy is currendy under evaluation as a tool for sucrose quantitation in sugar mills and food processing operations. 

Butenhoff et al. diseovered the near-infrared (NIR)-indueed tautomerism of H2P embedded in a hexane Shpol skii matrix [90SA(A)519] and gave a detailed deseription of its vibrational photoehemistry (90JPC7847). 

Another easy way of assembling a meaningless set of data is to work with a system for which you do not understand or control all of the important parameters. This would be easy to do, for example, when working with near infrared (NIR) spectra of an aqueous system. The NIR spectrum of water changes with changes in pH or temperature. If your measurements were made without regard to pH or temperature, the differences in the water spectrum could easily destroy any other information that might otherwise be present in the spectra. 

It is important to note that there are many publications which discuss optimal ways of selecting individual spectral wavelengths for use with ILS. Much of this work comes from the near infrared (NIR) community. It provides many examples of the power of intellegent wavelength selection. Unfortunately these methods often require more computional time and power than is convenient. 

The Advanced-Very-High-Resolution Radiometer (AVHRR) carried on board the NOAA-7 satellite has been collecting radiance data from the earth s surface since 1978. The polar-orbiting satellite records global data on a neardaily basis. The 4-kilometer data have been remapped by NO A A into monthly composites. The data are collected in 2 bands-one visible (VIS), the other near infrared (NIR). The Normalized Difference Vegetation Index, or NDVI, defined... 

Figure 2.9 Spectra of a single adenine nanocrystal, (a) TERS spectrum, (b) ordinal SERS spectrum, and (c) ordinary near-infrared (NIR) Raman spectra. For the SERS measurement, a silver island film was used. For the NIR Raman measurement, i thick sample of adenine was used with a 1 h exposure.

Intensified metabolic control, especially in case of diabetes, demands minimal-invasive or non-invasive methods of analytical measurement. For this goal, a method has been developed to measure the blood glucose content in vivo, in direct contact with the skin, by means of diffuse reflection near infrared (NIR) spectroscopy on the basis of multivariate calibration and neural networks (Muller et al. [1997] Fischbacher et al. [1997] Danzer et al. [1998]). Because no patients with any standard blood glucose value are available in principle, a method of indirect calibration has... 

Samola and Urleb [15] reported qualitative and quantitative analysis of OTC using near-infrared (NIR) spectroscopy. Multivariate calibration was performed on NIR spectral data using principle component analysis (PCA), PLS-1, and PCR. 

Changes of fibre optical properties and thus changes of the analyte can be detected in the ultraviolet (UV), visible (VIS), near infrared (NIR) and middle/far infrared (IR) regions. There are only a few materials sufficiently transparent in the UV region, and among them, the pure silica is uniquely suitable for fibre drawing. From Figure 5 it can be seen that the UV... 

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... 

The near-infrared (NIR) region (780 to 2500 nm) of the electromagnetic spectrum is situated between the visible light and mid-IR regions. With the introduction of efficient chemometric data... 

Such intervalence transitions are characterized by broad, intense and relatively featureless absorption bands in the UV, visible or near infrared (NIR). 

S. Coyle, T. Ward, C. Markham, and G. McDarby. On the suitability of near-infrared (nir) systems for next-generation brain-computer interfaces. Physiological Measurement, 25 815-822, 2004. 

Today, the IR region is divided into three distinct regions2 the near infrared (NIR), 900-2000nm the MIR, 4000-250cm and the far infrared (FIR), less... 

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