Raman spectral analysis

Howell, N.K., Arteaga, G.E., Nakai, S., and Li-Chan, E.C.Y. 1999. Raman spectral analysis in the C-H stretching region of proteins and amino acids for investigation of hydrophobic interactions. J. Agric. Food Chem. 47 924-933. 

Infrared and ultraviolet spectroscopy, including specific optical rotation, refractive index, and Raman spectral analysis... 

Infrared spectroscopy has been shown to spectrally discriminate normal and malignant tissues in conjunction with statistical analysis methods, many of these mathematical methods are applicable to Raman spectral analysis. 

Fig. 18.3. Raman spectral analysis of foetal osteoblast (FOB) differentiation. Unsupervised PCA of FOB cells cultured for 3 days in bioactive glass (BG) conditioned media (triangle) or control media (circle) (a). BG-treated cells formed a distinct cluster separate from control cells after 3 days culture. Least square (LS) analysis (which decomposes the cell spectra into the linear combination of Raman spectra obtained from the pure chemical constituents of the cell, e.g. nucleic acid, proteins, lipids, phospholipids and carbohydrates) of the relative RNA concentration of FOBs cultured for 1, 3 and 14 days in culture media (black) or BG condition media (grey), revealed a significantly reduced relative RNA concentration in FOBs culture in BG-conditioned media (b). FOBs cultured in BG-conditioned media appeared to accelerate FOB differentiation into mature adult osteoblast phenotypes (parallel gene and protein expression experiments confirmed this). Significant difference to control (p <0.05) [38]...

Cyclopropenone and its dideuterio equivalent 326 were subjected to rigorous infrared and Raman spectral analysis. Rather than the higher values reported above, the formal C=C stretch was found to be at 1483cm" in cyclopropenone and at 1409 cm" in 325. In addition these compounds have higher frequency bands at 1840 cm" and 1780 cm" ... 

The questions that may be asked in analysing the data measured by, say, a fibre-optic NIR or Raman spectral analysis system as described in Section 3.4.2 above are as follows. 

We were, thus, able to analyze the carbonization of the chitosan film with Kr+ ion bombardments as constitutional ratios of the depth profile from valence X-ray photoelectron and Raman spectral analysis in the nm and p,m ranges. Each constitutional ratio in the p,m range is (Chito DEC AC GP = 2 1 0.5 0.375), while the ratios in the nm range are (Chito DEC AC GP = 2 1 1 2). Thus, the graphite constitution of the carbonized film is small ratio of 0.375 in three kinds of carbon allotropes in the p.m range. On the other hand, the graphite ratio is around two times of other carbon allotropes in the nm range. 

V. Krishnakumar, S. Muthunatesan, G. Keresztury, and T. Sundius, Scaled quantum chemical calculations and FTIR, FT-Raman spectral analysis of 3,4-diamino benzophenone. Spectrochim. Acta A Mol. Biomol. Spectrosc. 62, 1081-1088 (2005). 

Secondary structure fractions were estimated by the Raman spectral analysis program of Przybycien and Bailey (1989), based on the algorithms of Williams (1983) for least-squares analysis of the Amide I band. 

Obviously, the application of multiple-wavelength excitations might prove very effective for characterization of ND by Raman spectral analysis. In disordered carbons, the G-peak position (Gpoj) increases as the excitation wavelength decreases, from IR to UV, as indicated by Ferrari and Robertson. The authors define G-peak dispersion (Gdisp) as a function of the excitation wavelength... 

One of the most difficult aspects of Raman spectral analysis is overcoming the often low signal levels present. Fortunately, many sources of noise are easily identifiable and straightforward to correct. Here, we will consider the noise which appears as random variations from point to point in a spectrum and varies from spectrum to spectrum in a consistent manner. Correction of changes in the total observed signal will be addressed in Section II.C. 

The direct determination of the structure by means of vibrational spectroscopy is impossible the structure must be known in advance by x-ray, electron, or neutron diffraction methods. Raman spectral analysis, sensu stricto, is based on group theory (see Sec. V.D) applied to isolated molecules or to crystal lattices triply periodic. Raman spectral analysis, sensu lato, includes the identification of the structure of an unknown material as being the same as that of a known material if their Raman spectra are identical this is the fingerprinting technique, which does not require knowledge of which vibration modes are concerned (see Sec. VI). 

Figure 12 Normal Raman spectral analysis of 60 mM metahydroxypyridine at pH 6.7 with 20-sec exposure and 30 scans at several temperatures.

Figure 15 Raman spectral analysis used in the characterization of the fractionation of humic substances. The bottom FT-Raman spectrum was taken at 1064-nm excitation and shows the 1326-cm" signature peak for disordered carbon networks. The top spectrum shows that after fractionation the 1326-cm peak has disappeared (or at least has been significantly reduced), and thus the disruption of the humic substance backbone is detected. (Reprinted with permission from YH Yang, HA Chase. Applications of Raman and surface enhanced Raman scattering techniques to humic substances. Spectr Lett 31 821-848, 1998. Copyright 1998 Marcel Dekker, Inc.)...

RH Clarke. Hydrocarbon analysis based on low resolution Raman spectral analysis. U.S. Patent 5,139,334, 1992. 

S.M. Lane et al. / Raman Spectral Analysis A Case Study... 

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