Sample preparation Raman spectrometry

Many methods have been developed to access the extent of oxidative deterioration, which are related to the measurement of the concentration of primary or secondary oxidation products or of both. The most commonly used are peroxide value (PV) that measures volumetrically the concentration of hydroperoxides, anisidine value (AV), spectrophotometric measurement in the UV region and gas chromatographic (GC) analysis for volatile compounds. Vibrational spectroscopy, because of its high content in molecular structure information, has also been considered to be useful for the fast measurement of lipid oxidation. In contrast to the time consuming chromatographic methods, modem techniques of IR and Raman spectrometry are rapid and do not require any sample preparation steps prior to analysis. These techniques have been used to monitor oil oxidation under moderate and accelerated conditions and the major band changes have been interpreted. ... 

See also ATR and Reflectance IR Spectroscopy, Applications Biochemical Applications of Raman Spectroscopy Food Science, Applications of Mass Spectrometry Food Science, Appiications of NMR Spectroscopy Fourier Transformation and Sampiing Theory FT-Raman Spectroscopy, Appiications iR Spectrometers, IR Spectroscopy Sample Preparation Methods IR Spectroscopy, Theory IR Spectral Group Frequencies of Organic Compounds Nonlinear Optical Properties Raman Optical Activity, Spectrometers Raman Spectrometers. 

With the exception of stilbene, all organic compounds listed in Table I (samples 14 to 28) were either obtained commercially or prepared by scientists at the USDA Forest Service, Forest Products Laboratory using well-established methods. Purchased chemicals were from both Aldrich Chemical Co., Milwaukee, Wisconsin, and Fluka Chemical Corporation, Ronkonkoma, New York. The Raman data for stilbene were taken from the literature [17]. Whenever the purity of a compound was in doubt, it was checked by gas chromatography-mass spectrometry. The Raman spectra reported here are from compounds that were more than 99% pure. 

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