Infrared microspectroscopy microscopy

Fourier transform infrared microspectroscopy couples both interferometry and microscopy into an integrated instmment. Since interferometry is an important... 

Therefore, by using this super-resolution infrared microscope, we will be able to carry out space- and time-resolved vibrational microspectroscopy in the IR super-resolved region. Given that IR absorption is regarded as the fingerprint of a molecule, the new super-resolution infrared microspectroscopy will become an extremely important tool, not only in microscopy but also in spectroscopy. 

Figure 3.1 is a scanning electron microscopy (SEM) photograph of Novozym 435 before and after immobilization of CALB on the matrix (Lewatit). It is obvious that after immobilization, the enzyme has been adsorbed on the surface of the matrix and the surface has been saturated. This observation confirms the results of synchrotron infrared microspectroscopy performed at amide band wavelength on Novozym 435 (Figure 3.2) [5, 6], The researchers measured the intensity of the amide band across the cross-section of a Novozym 435 bead and attributed the presence of amide groups to the location of the enzyme immobilized on the bead. They showed that distribution of CALB on the bead is not homogenous and it mostly saturates the surface of the beads and hardly enters the center. The CALB enzyme is a globular protein with dimensions of 30 A x 40 A x 50 A [10], whereas...

The distribution of enzyme in carriers is also critical to understanding catalyst activity. Jeroen van Roon, et al. quantitatively determined intraparticle enzyme distribution of Assemblase using light microscopy. They reported the enzyme was distributed heterogeneously and its concentration was radius-dependent. Our laboratory reported the use of infrared microspectroscopy for... 

Muto, J., Nagahama, H., Hashimoto, T. (2004). Microinfrared reflection spectroscopac mapping application to the detection of hydrogen-related species in natural quartz. Journal of Microscopy-Oxford, Vol. 216, pp. 222-228 Nakahara, M, Matubayasi, N., Wakai, C Tsujino, Y. (2001). Structure and dynamics of water from ambient to supercritical. Journal of Molecular Liquids, Vol. 90, pp. 75-83 Nakashima, S., Matayoshi, H., Yuko, T., Michibayashi, K., Masuda, T., Kuroki, N., Yamagishi, H., Ito, Y. Nakamura, A. (1995). Infrared microspectroscopy analysis of water distribution in deformed and metamorphosed rocks. Tectonophysics, Vol. 245, pp. 263-276... 

Figure 7.18 FTIR microscopy spectra of leaves from (a) old and (b) young alfalfa plants [53]. Reprinted from Fuller, M. P. and Rosenthal, R. J., Biological Applications of FTIR Microscopy , in Infrared Microspectroscopy Theory and Applications, Messer-schmidt, R. G. and Harthcock, M. A. (Eds), Figure 6, p. 160 (1988), courtesy of Marcel Dekker, Inc.

Fraser DJJ, Norton KL, and Griffiths PR (1988) HPLC/FT-IR measurements by transmission, reflection-absorption, and diffuse reflection microscopy. In Messerschmidt RG and Harthcock MA (eds.) Infrared Microspectroscopy Theory and Applications, pp. 197-210. New York Dekker. 

These examples cQso illustrate the difference in spatial resolution and contrast mechanisms between optical and infrared microscopies. While optical microscopy is capable of higher spatial resolution, its discrimination is limited to a difference in the average of a property of materials, namely refractive index, unless specially labeled to detect a property of the label. Infrared microspectroscopy derives its contrast mechanism from the intrinsic composition of the material but suffers from a poorer spatial resolution. A judicious use of the two complementary techniques is often required to achieve good characterization. While the example above illustrated the detection of differences, FTIR microspectroscopy can also be used to determine homogeneity. For example, compositional differences in a PP-PE film could not be detected between the surface and up to 500 pm into the bulk of the sample [61]. 

Merging of spectroscopy with microscopy has generated an entirely new discipline, termed microspectroscopy, which allows measurement of the spatial distribution of chemical stractures in materials. Microspectrophotometry (MSP), primarily in the UVAHS and NIR ranges (220 to 2500 nm), has been practised in some way since the 1930s with emphasis on the microscope functionality [368, 369]. On the other hand, the recent convergence of infrared with microscopy accentuates the spectroscopic functionality. Microspectroscopy is a powerful tool for characterisation of micro samples, for examination of heterogeneous materials and for analysis of processes such as migration that involve spatial... 

Principles and Characteristics Infrared microspectroscopy can be considered as the coupling of a microscope to an infrared spectrometer. Another definition of IR microspectroscopy is the study of how infrared radiation interacts with microscopic particulates. Indeed, diffraction, refraction, reflection, and absorption effects play a much more important role in microspectroscopy than in its macroscopic counterpart. Infrared microscopy... 

Infrared microspectroscopy has been reviewed [436,444 47] and theory and applications have been described in several recent books [393,417-419], An introduction to step-scan FTIR is available [448]. The role of IR and Raman microscopy/ microprobe spectroscopic techniques in the characterisation of polymers, their products, and composites was reviewed [449]. McClure [450] has described NIR imaging spectroscopy and a recent review on time-resolved studies of polymers by mid-and near-infrared spectroscopy has appeared [451]. Near-infrared microspectroscopy and its applications have been reviewed [452]. 

This technique demonstrates the potential in combining the spatial specificity of microscopy with the powerful chemical specificity of spectroscopy. A balance between the need for sensitive spectral information and a need for high spatial resolution visualization is also necessary for morphological characterization. Hence, infrared microspectroscopy is performed in sequence with emphasis placed on instrumentation capabilities and experimental possibilities. 

As noted above, the best spatial resolution of a microscope is ultimately determined by diffraction of the radiation. Thus, the spatial resolution is limited by the radius r of the Airy disk for the longest wavelength in the spectrum and hence depends on n, the refractive index of the medium in which the optics are immersed, for example, 1.0 for air and up to 1.56 for oils. Oil immersion is almost never used for infrared microspectroscopy because of absorption by the oil but has occasionally been used to improve the spatial resolution in Raman microspectroscopy. Immersion oils have been shown to be essential in order to obtain good depth resolution with confocal Raman microscopy [21]. Of greater importance from a practical standpoint for infrared microspectroscopy is the improvement in spatial resolution that is achieved in an attenuated total reflection (ATR) measurement with a hemispherical IRE, especially when the IRE is fabricated from germanium ( = 4.0) or silicon (n = 3.4.)... 

In many studies, particularly those related to materials and forensic science, it is frequently necessary to measure a mid-infrared spectrum from a trace amount of a sample or a sample of small size. In some circumstances, this may be accomplished by using a beam-condenser accessory within the conventional sample compartment of a Fourier-transform infrared (FT-IR) spectrometer. Perhaps today though, it is more convenient to use infrared microspectrometry (often commonly referred to as infrared microspectroscopy or even infrared microscopy). Based on an optical microscope (or infrared microscope) coupled to an FT-IR spectrometer, it is one of the most useful methods for structural analysis of such samples and can often be undertaken in a non-destructive manner [1, 2]. 

Infrared Microscopy Also known as infrared microspectroscopy. The technique of using an infrared microscope to obtain the infrared spectrum of microscopic samples. 

Infrared microscopy is well suited for in situ analysis of contaminants fount in pharmaceutical processes. Due to the nondestructive nature of the analysis further experiments such as energy dispersive x-ray analysis may be performer on the same sample once IR investigations are complete. To illustrate the potentia of IR microspectroscopy, one application from the Bristol-Myers Squibl laboratories is presented. 

Microscopy technologies, polymer analysis using, 79 567-568 Micro-Sect formulation, 7 564t Microsilica, world demand for, 22 497 Microspectrometers, 76 484-485 Microspectroscopy, infrared, 76 486... 

---