Fourier transform near-infrared Raman

Fourier Transform Near-Infrared Raman Spectroscopy... 

The advantages of Fourier transform near-infrared Raman spectroscopy are ... 

Aghenyega and co-workers [24] have investigated the application of Fourier transform near-infrared Raman spectroscopy in the synthetic polymer field. Their investigations covered the following areas ... 

B. Chase, Fourier transform near-infrared Raman spectroscopy, in Handbook of Vibrational Spectroscopy, J. C. Chalmers and P. R. Griffiths, Eds., Wiley, Chichester, West Sussex, England, 2002, Vol. 1, p. 522. 

Under non-resonant conditions, quantum yields for the Raman effect are in the order of 10 , implying that sample concentrations in the millimolar range are required for obtaining Raman spectra of satisfactory quality. Resonance enhancement substantially improves the sensitivity, but even RR intensities are too weak to obtain spectra of samples which exhibit a strong fluorescence or which contain strongly fluorescent impurities. In those cases, Fourier-transform near-infrared Raman spectroscopy may be a useful alternative approach. 

Fourier transform near-infrared spectroscopy had been used to determine traces of hydroxy and carboxy functional groups and water in polyesters. Bowden and co-workers [25] monitored the degradation of PVC using Raman microline focus spectrometry. They demonstrated that PVC decomposition is accompanied by the formation of modal polyene chains containing 11-12 or 13-19 double bonds. Bloor [26] has discussed the Fourier transform Raman spectroscopy of polydiacetylenes. Koenig [27] discusses results obtained by the application of infrared and Raman spectroscopy to polymers. 

Choquette, S. J., et al. "Identification and Quantitation of Oxygenates in Gasoline Ampules Using Fourier Transform Near-Infrared and Fourier Transform Raman Spectroscopy." Analytical Chemistry, 681996,3525-3533. 

I J Williams, RE Aries, DJ Cutler, DP Lidiard. Determination of gas oil cetane number and Cetane Index using near-infrared Fourier transform Raman spectroscopy. Anal Chem 62 2553-2556, 1990. MB Seasholtz, DD Archibald, A Lorber, BR Kowalski. Quantitative analysis of liquid fuel mixtures with the use of Fourier transform near-IR Raman spectroscopy. Appl Spectrosc 43 1067-1072, 1989. 

SJ Choquette, SN Chester, DL Duewer, S Wang, TC O Haver. Identification and quantitation of oxygentates in gasoline ampules using Fourier transform near-infrared and Fourier transform Raman spectroscopy. Anal Chem 68 3525-3533, 1996. 

In order to demonstrate the usefulness of the method, SERS spectra of indolino-spironaphthopyran (SPP, 4) and indolino-spironaphthoxazine (SPOX, 3) (see Scheme 7) were recorded at low concentration (10 7-10-8 A/) and their spectral characteristics analysed.48 Figure 8 shows the SERS spectrum of 4 in Ag colloids (spectrum a) along with the corresponding near-infrared Fourier transform (NIR-FT) Raman spectrum of the neat compound (spectrum b). Strong differences between the SERS and spontaneous Raman spectra are apparent. As stated above, these differences arise mainly from the particular orientation of the adsorbed spiropyran with to the metal surface in SERS experiments. 

Fourier transform mid-infrared (FTIR), near-infrared (FTNIR), and Raman (FT-Raman) spectroscopy were used for discrimination among 10 different edible oils and fats, and for comparing the performance of these spectroscopic methods in edible oil/fat studies. The FTIR apparatus was equipped with a deuterated triglycine sulfate (DTGS) detector, while the same spectrometer was also used for FT-NIR and FT-Raman measurements with additional accessories and detectors. The spectral features of edible oils and fats were studied and the unsaturation bond (C=C) in IR and Raman spectra was identified and used for the discriminant analysis. Linear discriminant analysis (LDA) and canonical variate analysis (CVA) were used for the disaimination and classification of different edible oils and fats based on spectral data. FTIR spectroscopy measurements in conjunction with CVA yielded about 98% classification accuracy of oils and fats followed by FT-Raman (94%) and FTNIR (93%) methods however, the number of factors was much higher for the FT-Raman and FT-NIR methods. 

Sockalingum, D., Fleischmaim, M. and Musiani, M.M. (1991) Near-infrared Fourier transform surface-enhanced Raman scattering of azole copper corrosion inhibitors in aqueous chloride media. Spectrochimica Acta Part A Molecular and Biomolecular, 47, 1475-1485. 

C.M. Deeley, R.A. Spragg and T.L.A. Threlfall, Comparison of Fourier transform infrared and near-infrared Fourier transform Raman spectroscopy for quantitative measurements an application, Spectrochim. Acta, Part A, 47A, 1217-1223 (1991). 

However, the high frequency of the laser irradiation in the visible region may lead to photochemical reactions in the laser focus. Besides, fluorescence can often cover the whole Raman spectrum. Such problems can be avoided by using an excitation wavelength in the near-infrared (NIR) region, e.g. with an Nd YAG laser operating at 1064 nm. Deficits arising from the v dependence of the Raman intensity and the lower sensitivity of NIR detectors are compensated by the Fourier-Transform (IT) technique, which is widespread in IR spectroscopy . ... 

Fourier-Transform Infrared (FTIR) spectroscopy as well as Raman spectroscopy are well established as methods for structural analysis of compounds in solution or when adsorbed to surfaces or in any other state. Analysis of the spectra provides information of qualitative as well as of quantitative nature. Very recent developments, FTIR imaging spectroscopy as well as Raman mapping spectroscopy, provide important information leading to the development of novel materials. If applied under optical near-field conditions, these new technologies combine lateral resolution down to the size of nanoparticles with the high chemical selectivity of a FTIR or Raman spectrum. These techniques now help us obtain information on molecular order and molecular orientation and conformation [1],... 

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