NIRS technology determination

Since the first-ever application of NIR by Hart et al. in 1962 to the determination of moisture in seeds (6), the bibliography of NIRS technology has proliferated until it now numbers over 35,000 entries, many of which describe a very diverse assortment of applications to grains and seeds. The main areas have been composition analysis, analysis for prediction of functionality, and classification by NIR discriminant or classification analysis (NIRCA). Near-infrared spectroscopy has been applied to the analysis of many of the above commodities. Over 30 factors have been successfully predicted in cereals and pulses, and over 20 factors in oleaceous seeds. These applications have recently been comprehensively reviewed by Delwiche (7) and Dyer (8). 

TABLE 7.1.4. Applications of NIR Technology to Determination of Composition of Pulse Crops... 

Several papers have been published in which, instead of concentrating on specific reactions, the technology was highlighted. One, by Marose et al.,7 discusses the various optics, fiber optics, and the probe designs that allow in situ monitoring. They describe the various optical density probes used for biomass determination in situ microscopy, optical biosensors, and specific sensors such as NIR and fluorescence. 

Sukowski, L., NIR Based Process Analytical Technology In-line Residual Moisture Determination for a Complete Batch Inspection of Lyophilized End-Products. Thesis, Basel (2003). 

Use of a refractive near-infrared (NIR) moisture sensor for end-point determination of wet granulation was described by several authorsJ " There are technological challenges associated with this approach, as the sensor can only measure the amount of water at the powder surface. 

As an example for multivariate modeling, we consider the simultaneous determination of several components in low-selective analytical systems (multicomponent analysis). These components can be elements, compounds, or chemical/physical properties. By means of multicomponent analysis, constituents of pharmaceutical formulations can be determined in the UV range, the water and protein content of cereal can be estimated from NIR spectra or chemical elements, and technological parameters of coal are predictable on the basis of infrared (IR) spectra. The limited selectivity of chemical sensors can also be overcome by applying the principles of multicomponent analysis. 

Pesticide concentration can be readily measured with NIR spectroscopy and optical imaging technology. However the accuracy and precision could be impa-oved. There is a need to develop rapid optical techniques for pesticide determination which could be used in the future for agro-food safety assurance. The optical technique could be one of the most useful tools along with the advancement of spectral instrument for determination of p>esticide residue. 

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