Near infra-red

Here a ehemieal reaetion produees a moleeule with eleetrons in an exeited state. Upon deeay to the ground state the liberated radiation is deteeted. One sueh example is the reaetion between ozone and nitrie oxide to form nitrogen dioxide emitting radiation in the near infra-red in the 0.5-3/x region. The teehnique finds use for measuring nitrie oxide in ambient air or staek emissions. 

Ultrasound and X-ray equipment are examples of diagnostic medical devices. In-vitro medical devices are distinguished from other diagnostic medical devices, in that a specimen must first of all be removed from the donor. A device worn by a diabetic that continually monitors their glucose via a non-invasive method (near-infra-red energy emissions) would be just regulated as a medical device, whereas a glucosemonitoring device that used a lancet to obtain a blood sample would be an IVD. 

Selectivity and Interference Selectivity means that only that species is measured which the analyst is looking for. A corollary is the absence of chemical interferents. A lack of selectivity is often the cause of nonlinearity of the calibration curve. Near infra-red spectroscopy is a technology that exemplifies how seemingly trivial details of the experimental set-up can frustrate an investigator s best intentions Ref. 124 discusses some factors that influence the result. 

In recent studies on perfused rats hearts (Veitch et al., 1992), it was found that differences in the sensitivity of complexes 1-lV to ischaemic damage were dependent upon the duration of ischaemia and the presence of oxygen. The demonstration that complex 1 is a major defective site dependent upon isolation of mitochondria from homogenates of the tissue by in vitro methods seemed important to us. We therefore decided to attempt to make noninvasive measurements of mitochondrial function soon after reperfusion in transplanted rabbit kidneys by surface fluorescence (for mitochondrial NADH levels) and near infra-red spectroscopy (NIRS) for the redox state of cytaas. 

A. de Juan, G. Fonrodona and E. Casassas, Solvent classification based on solvatochromic parameters a comparison with the Snyder approach. Trends Anal. Chem., 16(1) (1997) 52-62. T. Naes, The design of calibration in near infra-red reflectance analysis by clustering. J. Chemom., 1 (1987) 129-134. 

K.I. Hildrum, T. Isaksson, T. Naes and A. Tandberg, Near Infra-red Spectroscopy Bridging the Gap between Data Analysis and NIR Applications. Ellis Horwood, New York, 1992. 

MLCT metal-to-ligand charge transfer MRI magnetic resonance imaging NIR near-infra red NMR nuclear magnetic resonance... 

The large majority of analytical applications are limited to middle infrared region. But in recent years interest has developed in near infra red and far infrared regions. 

Rurack K, Resch-Genger U, Bricks JL et al (2000) Cation-triggered switching on of the red/near infra-red (NIR) fluorescence of rigid fluorophore-spacer-receptor ionophores. Chem Commun 2103-2104... 

The quantized nature of electronic energy levels due to size confinement is amplified in this term. They show characteristic absorption features and can be distinguished from each other from their absorption profiles [2], Quantum clusters typically exhibit strong photoluminescence and their wavelength of emission can be tuned from the near infra red (NIR) to ultra violet (UV) [1]. 

P. Frake, D. Greenhalgh, S.M. Grierson, J.M. Hempenstall and D.R. Rudd, Process control and end-point determination of a flnid bed granulation by apphcation of near infra-red spectroscopy, Int. J. Pharm., 151, 75-80... 

R. Gimet and A.T. Luong, Quantitative determination of polymorphic forms in a formulation matrix using the near infra-red reflectance analysis technique, J. Pharm. Biomed. Anal, 5, 205-211 (1987). 

The philosophies for automation have been described in the foregoing sections. However, to solve an analytical problem there may well be more than one approach that offers potential. The Hterature abounds with methods that have been automated by flow-injection and by continuous-flow methodologies. Also, very often a procedure which involves several stages prior to the actual measurement can be configured by combining two of the approaches. An example of this is the automated Quinizarium system described by Tucker et al. [46]. This was a continuous extraction followed by a hatch extraction which is finally completed by a batch measurement on a discrete sample for quantification and measurement. Whereas sample preparation is almost always required, there is no doubt in my mind that the best approach to this area of activity is to avoid it totally. The application of near infra-red spectroscopy is an example of this strategy. 

Near infra-red reflectance spectroscopy was first used by Norris and Hart [54] for the determination of moisture, oil and fat in cereal products. A number of instrument companies, notably Technicon, have developed commercial instruments. The instrument replaces a series of chemical procedures by a signal measurement in each of six infra-red regions and reference to a suitable computer calibration. Such an approach offers... 

Baker, C.W. and Givens, D.l. (1992) The use of near infra-red reflectance spectroscopy (NIRS) for the evaluation of forages the application to undried silage. Animal Production 54, 507 (Abstract). 

Hildrum, K.I., Isaksson, T., Naes, T. and Tandberg, A. (1992) Near Infra-red Spectroscopy. Ellis Norwood, New York. 

Parnell, A. and White, J. (1983) The use of near infra-red reflectance analysis in predicting the digestibility and the protein and water soluble carbohydrate contents of perennial ryegrass. Journal of the National Institute of Agricultural Botany 16, 221-227. 

European Pharmacopoeia Near Infra Red Spectrometry June 2004 59. Choppin G, Buijs K. Near infrared studies of structure of water-II. Ionic Solutions. J Chem Phys 1963 39 2042-2050. 

For drying of expls at the plant, Olsen patented (Ref 7) the following method Grains of an expl, deposited in a layer l/8 to 1/2 inch thick on a belt, travel for about 95 mins thru a radiation chamber, ca 30 ft long, maintained at 65—75°C. Heating is produced by radiationwhich is nearly infra-red... 

The nature of the cure reactions in these epoxies can be confirmed by monitoring the epoxide consumption via near infra-red spectroscopy for a series of epoxide-amine mixtures containing a range of amine contents. A plot of % epoxide consumption vs. amine concentration for DGEBA-T403 epoxies is illustrated in Fig. 2. This plot confirms that the DGEBA-T403 epoxy system forms exclusively from epoxide-amine addition reactions, because (i) 100% epoxide consumption is attained at the stoichiometric amine concentration associated with exclusive epoxide-amine addition cure reactions and (ii) extrapolation of this plot to zero amine content indicates there is no epoxide consumption i.e. there are no epoxide homopolymerization reactions. 

---