Adulteration of diesel/biodiesel blends by vegetable oil as determined by Fourier transform (FT) near infrared spectrometry and FT-Raman spectroscopy

2007 ◽  
Vol 587 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Flavia C.C. Oliveira ◽  
Christian R.R. Brandão ◽  
Hugo F. Ramalho ◽  
Leonardo A.F. da Costa ◽  
Paulo A.Z. Suarez ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Vegetable Oil ◽  
Near Infrared ◽  
Infrared Spectrometry ◽  
Biodiesel Blends ◽  
Ft Raman Spectroscopy ◽  
Near Infrared Spectrometry ◽  
Ft Raman

Potential of Near-Infrared Fourier Transform Raman Spectroscopy in Food Analysis

1992 ◽  
Vol 46 (10) ◽  
pp. 1503-1507 ◽  
Author(s):  
Y. Ozaki ◽  
R. Cho ◽  
K. Ikegaya ◽  
S. Muraishi ◽  
K. Kawauchi
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Fatty Acid ◽  
Raman Spectra ◽  
Food Analysis ◽  
Near Infrared ◽  
Egg White ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

The 1064-nm excited Fourier transform (FT) Raman spectra have been measured in situ for various foods in order to investigate the potential of near-infrared (NIR) FT-Raman spectroscopy in food analysis. It is demonstrated here that NIR FT-Raman spectroscopy is a very powerful technique for (1) detecting selectively the trace components in foodstuffs, (2) estimating the degree of unsaturation of fatty acids included in foods, (3) investigating the structure of food components, and (4) monitoring changes in the quality of foods. Carotenoids included in foods give two intense bands near 1530 and 1160 cm−1 via the pre-resonance Raman effect in the NIR FT-Raman spectra, and therefore, the NIR FT-Raman technique can be employed to detect them nondestructively. Foods consisting largely of lipids such as oils, tallow, and butter show bands near 1658 and 1443 cm−1 due to C=C stretching modes of cis unsaturated fatty acid parts and CH2 scissoring modes of saturated fatty acid parts, respectively. It has been found that there is a linear correlation for various kinds of lipid-containing foods between the iodine value (number) and the intensity ratio of two bands at 1658 and 1443 cm−1 ( I1658/ I1443), indicating that the ratio can be used as a practical indicator for estimating the unsaturation level of a wide range of lipid-containing foods. A comparison of the Raman spectra of raw and boiled egg white shows that the amide I band shifts from 1666 to 1677 cm−1 and the intensity of the amide III band at 1275 cm−1 decreases upon boiling. These observations indicate that most α-helix structure changes into unordered structure in the proteins constituting egg white upon boiling. The NIR FT-Raman spectrum of old-leaf (about one year old) Japanese tea has been compared with that of its new leaf. The intensity ratio of two bands at 1529 and 1446 cm−1 ( I1529/ I1446), assignable to carotenoid and proteins, respectively, is considerably smaller in the former than in the latter, indicating that the ratio is useful for monitoring the changes in the quality of Japanese tea.

FT-Raman Spectroscopy at 1.339 Micrometers

1994 ◽  
Vol 48 (6) ◽  
pp. 699-701 ◽  
Author(s):  
Kelly J. Asselin ◽  
Bruce Chase
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Near Infrared ◽  
Copper Phthalocyanine ◽  
Fourier Transform Raman Spectroscopy ◽  
Ft Raman Spectroscopy ◽  
Anti Stokes ◽  
Fourier Transform Raman ◽  
Ft Raman

The usual laser employed for Fourier transform Raman spectroscopy is a Nd:YAG unit lasing at 1.064 μm. In this work, use of the 1.339-μm lasing emission from Nd:YAG has been demonstrated. The sensitivity of this instrument is comparable to that of conventional FT-Raman instruments, and excellent anti-Stokes spectra can be easily obtained. Operation further into the near-infrared offers additional possibilities for fluorescence minimization. Results are shown for copper phthalocyanine.

The structure of the kaolinite minerals — a FT-Raman study

Clay Minerals ◽  
1997 ◽  
Vol 32 (1) ◽  
pp. 65-77 ◽  
Author(s):  
R. L. Frost
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Near Infrared ◽  
Hydroxyl Groups ◽  
Kaolinite Clay ◽  
Fourier Transform Raman Spectroscopy ◽  
Ft Raman Spectroscopy ◽  
The Fourier Transform ◽  
Fourier Transform Raman ◽  
Ft Raman

AbstractThe Fourier transform Raman spectra of the kaolinite minerals have been measured in the 50–3800 cm−1 region using near infrared spectroscopy. Kaolinites are characterized by remarkably intense bands in the 120–145 cm−1 region. These bands, attributed to the O-Si-O and O-Al-O symmetric bending modes, are both polymorph and orientation dependent. The 200–1200 cm−1 spectral range is a finger-print region for clay minerals and each kaolinite clay has its own characteristic spectrum. The structure of clays is fundamentally determined by the position of hydroxyl groups. Fourier-transform Raman spectroscopy readily enables the hydroxyl stretching region to be examined allowing identification of the component bands. The advantages of FT-Raman spectroscopy are shown to enhance the study of the kaolinite structure.

Development of Near-Infrared Fourier Transform Raman Spectroscopy for the Study of Biologically Active Macromolecules

1988 ◽  
Vol 42 (7) ◽  
pp. 1188-1193 ◽  
Author(s):  
E. Neil Lewis ◽  
V. F. Kalasinsky ◽  
Ira W. Levin
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Lipid Bilayers ◽  
Near Infrared ◽  
Optical Design ◽  
Membrane Lipid ◽  
Biologically Active ◽  
Fourier Transform Raman Spectroscopy ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

General advantages and potential limitations of Fourier transform (FT) Raman spectroscopy using Nd:YAG laser excitation at 1064 nm have been considered for both routine analysis and specific biophysical applications. Optical design and operating parameters which affect the quality and reproducibility of the data are discussed. Moderately high resolution spectra (0.25 cm−1) of liquids are obtained with relative ease, and the results are compared with dispersive spectra. Particular emphasis has been placed on applications to biological systems where intrinsic fluorescence has traditionally limited the use of dispersive Raman spectroscopy. As an example of a biophysical study, we demonstrate the utility of FT-Raman spectroscopy in elucidating the interactions of polyene antibiotics with model membrane lipid bilayers as a means of understanding novel drug/membrane interactions at the molecular level.

Biological applications of near- IR fourier-transform Raman microspectroscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1530-1531
Author(s):  
Yukihiro Ozaki
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Photosynthetic Bacteria ◽  
Near Infrared ◽  
Raman Microspectroscopy ◽  
Excitation Wavelength ◽  
Near Ir ◽  
Ft Raman Spectroscopy ◽  
Sample Position ◽  
Ft Raman

Recently-developed near-infrared Fourier transform (FT)-Raman spectroscopy has received keen interest of researchers in bio-Raman field because near-infrared excitation can avoid mostly fluorescence and photodecomposition, which have been two major drawbacks of Raman spectroscopy in its biological and medical applications. Introduction of FT-Raman microspectroscopy makes near-infrared FT-Raman spectroscopy more useful for studying biomedical materials. The purpose of the present paper is to demonstrate the potential of near-infrared FT-Raman microspectroscopy in nondestructive structural analysis of biological systems. Photosynthetic bacteria is taken up here as an example.The FT-Raman spectra of the photosynthetic bacteria were measured with a JEOL JRS-FT6500N FT-Raman spectrometer equipped with an optical microscopy. Excitation wavelength at 1064-nm was provided by a CW Nd:YAG laser (CVI YAGMAX c-92), and the laser power at the sample position was typically 150 mW. All the data were collected at a spectral resolution of 8 cm-1 and spatial resolution of 8 μm.

Application of FT-Raman spectroscopy to the study of selected organometallic complexes and proteins

1990 ◽  
Vol 68 (7) ◽  
pp. 1196-1200 ◽  
Author(s):  
Steven M. Barnett ◽  
François Dicaire ◽  
Ashraf A. Ismail
Keyword(s):  
Raman Spectroscopy ◽  
Near Infrared ◽  
Metal Carbonyl ◽  
Protein A ◽  
Organometallic Complexes ◽  
Laser Source ◽  
Chromium Tricarbonyl ◽  
Ft Raman Spectroscopy ◽  
Arene Chromium Tricarbonyl ◽  
Ft Raman

The study of colored organometallic complexes by dispersive Raman spectroscopy has been limited due to fluorescence or photodecomposition caused by the visible laser used as the excitation source. As a solution to this problem, FT-Raman spectroscopy with a near-infrared laser source has been useful in lowering fluorescence or photolysis in these samples. To investigate the utility of this technique, we have obtained and assigned the FT-Raman spectra of a series of arene chromium tricarbonyl complexes and of cyclopentadienyl manganese tricarbonyl. Some bands previously unobserved by dispersive Raman spectroscopy were seen, including a band assigned to a 13CO satellite in the spectrum of methylbenzoate chromium tricarbonyl. In addition, FT-Raman data for bovine serum albumin (BSA) and Protein-A are presented. Keywords: FT-Raman spectroscopy, metal carbonyl, proteins, organometallics, near infrared.

Signal-to-Noise Considerations in FT-Raman Spectroscopy

1989 ◽  
Vol 43 (5) ◽  
pp. 778-781 ◽  
Author(s):  
N. J. Everall ◽  
J. Howard
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Theoretical Analysis ◽  
Shot Noise ◽  
Noise Equivalent Power ◽  
Raman Signal ◽  
Signal To Noise ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

A simplified theoretical analysis of the S/N performance of Fourier transform (FT) Raman spectrometers compared with conventional scanning machines is presented. Calculations indicate that the multiplex gain may be significantly degraded due to the shot noise from the Raman signal, and this situation is exacerbated when Rayleigh radiation reaches the detector. It is expected that use of detectors with a noise equivalent power of 10−15 W would largely eliminate any multiplex gain in FT-Raman spectroscopy.

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