NIR chemical imaging

This need is addressed in part by NIR-CI, in that it offers the ability to obtain high fidelity, spatially resolved pictures of the chemistry of the sample. The ability to visualize and assess the compositional heterogeneity and structure of the end product is invaluable for both the development and manufacture of solid dosage forms. NIR chemical images can be used to determine content uniformity, particle sizes and distributions of all the sample components, polymorph distributions, moisture content and location, contaminations, coating and layer thickness, and a host of other structural details. "... 

Figure 8.1 Schematic representation of NIR chemical imaging instrument operating in diffuse reflectance mode. Radiation from the illumination source interacts with the sample. Light reflected off of the sample is focused onto a NIR sensitive 2D detector after passing through a solid-state tunable wavelength selection filter.

While this is not the place for a complete description of the theory, uses, and ramihcations of all possible processing treatments that can be applied to chemical imaging data, the majority of NIR chemical images recorded to date have been obtained from solid or powder samples, measured predominantly by diffuse reflectance. As such, the following discussions may serve as a general outline of the more common procedures and their applications to these types of imaging data. 

Figure 8.9 (a) Single wavelength NIR chemical image at 2070nm showing tablet coating differences between... 

Here, we provide examples of various paths of development leading to NIR imaging methods that have been described for the analysis of corn. Although these examples focus on a single commodity, the approaches are universal and provide a good overview of possibilities for the development of NIR chemical imaging... 

Factors to Consider in the Development of NIR Chemical Imaging Methods... 

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