Data Raman image

L. Zhang, M. Henson and S. Sekulic, Multivariate data analysis for Raman imaging of a model pharmaceutical tablet. Anal Chim. Acta, 545(2), 262-278 (2005). 

Fiber Bundles Fiber bundles are used for Raman imaging. Several optical fibers are grouped together, each analyzing a specific sample area [13]. A 3D data cube is... 

In particular, because of their high structural selectivity, Raman and IR imaging techniques also have the capability to monitor chemical structural changes that occur in chemical and physical processes. Both IR and Raman imaging techniques benefit from recent developments of array detectors, which allow the rapid collection of both spectral and positional data. 

Figure 3-38 AOTF Raman spectra of (A) DPPC and (B) L-asparagine in the CH and NH stretching Region. These spectra were obtain from the AOTF Raman image data at pixels corresponding to DPPC and L-asparagine, respectively. (Reproduced with permission from Ref. 101.)...

Both optical and mechanical line scans generate large data sets when used to construct a two-dimensional Raman image, but computer power and storage is inexpensive in the post-PC world. An advantage of such large data sets is the retention of complete spectra for each spatial element, with often high spectral... 

Colon tissue was selected as a model for the comparative analysis of soft tissue by FT-IR and Raman imaging at low and high lateral resolution, because it contains aU four major tissue types such as muscle, connective tissue, epithelium and also nerve cells. The vibrational spectroscopic fingerprints of normal tissues and their distribution in control samples were determined. The compilation of such data is important before a method can be applied to pathological colon tissue such as colorectal adenocarcinoma, which is the third most common form of cancer and the second leading cause of death among cancer patients in the Western world. Colorectal adenocarcinomas originate from epithelial cells and are able to infiltrate the subjacent layers of colon and rectum. 

The Raman image in Figure 11.14b encompasses 7.4 X 6.2 mm mapped with 75 gm steps hence, a Raman spectrum is measured at every 75 gm in the mapping area. These data are excellent for assessing the overall characteristics of the sample and identifying the ROI. 

The incorporation of high-resolution optics in a Raman spectrometer allows sampling from areas of less than 1 x 10 m in diameter. The addition of a confocal microscope improves the axial resolution to a couple of microns. Those developments, along with the introduction of notch filters and holographic transmission gratings, allow the reduction of the acquisition time of Raman spectra from minutes to seconds. The fast data collection combined with the high lateral and vertical resolutions makes possible the collection of Raman images with several micron spatial resolutions. 

Two alternative methods of Raman imaging via global illumination and via point illumination in combination with confocal light collection were applied to the study of heterogeneous polymer systems. The spectral and spatial resolving power of the different techniques was estimated experimentally. The influence of the depth resolution on the Raman image of a defined sample structure was demonstrated in a mathematical simulation. Data are given for PE, PS, polyacrylate, and epoxy resins. 23 refs. 

A fast NIR Raman imaging microscope system (NIRIM) is described by McLain and coauthors that uses a fiber-optic bundle and CCD detector to collect a complete 3D Raman data cnbe from a sample in 1 s or less. A schematic of the NIRIM is shown in Figure 4.81. The system has been nsed... 

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