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.

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.

Time-Resolved and Two-Dimensional NIR FT-Raman Spectroscopy

1993 ◽  
Vol 47 (9) ◽  
pp. 1452-1456 ◽  
Author(s):  
B. Schrader ◽  
G. Baranović ◽  
A. Epding ◽  
G. G. Hoffmann ◽  
P. J. M. Van Kan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Near Infrared ◽  
Initial Letter ◽  
Inorganic Pigment ◽  
Time Resolved ◽  
Sample Distribution ◽  
Merocyanine 540 ◽  
Scattering Geometry ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

The near-infrared Fourier transform (NIR FT) Raman technique permits the measurement of Raman spectra without interference by fluorescence. Absorption by molecules containing X-H bonds in the NIR range requires a 180° scattering geometry. In this way, Raman spectroscopy of samples on surfaces is possible, both the detecting of small spots and the mapping of the sample distribution over larger areas. The spatial resolution extends into the micrometer range. Mapping of the inorganic pigment distribution of an initial letter of a mediaeval manuscript is demonstrated. For time-resolved measurements, the step-scan technique, previously developed for infrared spectroscopy, may be used in NIR FT-Raman spectroscopy as well. It allows the study of photochemical and photophysical processes, the application of modulation techniques, and the investigation of “noisy” samples. Photo-isomerization of the dye merocyanine 540 has been observed with the step-scan technique upon periodic excitation with a flash lamp.

Near-infrared FT-Raman spectroscopy of living photosynthetic bacteria

1993 ◽  
Author(s):  
Yukihiro Ozaki ◽  
H. Sato ◽  
K. Okada ◽  
Y. Koyama ◽  
K. Uehara
Keyword(s):  
Raman Spectroscopy ◽  
Photosynthetic Bacteria ◽  
Near Infrared ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

Discrimination between Glutinous and Non-Glutinous Rice by Vibrational Spectroscopy. I: Comparison of FT-NIR DRIFT, PAS and Raman Spectroscopy

1998 ◽  
Vol 6 (1) ◽  
pp. 241-249 ◽  
Author(s):  
Yoshisato Ootake ◽  
Serge Kokot
Keyword(s):  
Raman Spectroscopy ◽  
Water Content ◽  
Near Infrared ◽  
Amylose Content ◽  
Spectroscopic Techniques ◽  
Glutinous Rice ◽  
Ft Raman Spectroscopy ◽  
Diffuse Reflectance Infrared ◽  
Ft Raman

Rice is a major cereal crop in Japan and in Asia. Its taste is determined by such factors as protein and water content as well as stickiness. It has been well established that protein and water content can be estimated by near infrared spectroscopic measurements. However, the measurement of amylose content, which is closely related to rice stickiness, at present, must be carried out by wet chemical methods. Vibrational spectroscopic techniques are possible alternative approaches for the determination of amylose content in rice and, in this paper, we report on the initial steps for the development of methodology for this purpose, namely on the comparison of FT-NIR DRIFT (Diffuse Reflectance Infrared Fourier Transform Spectroscopy), PAS (Photo-Acoustic spectroscopy) and FT-Raman spectroscopy for the discrimination of glutinous and non-glutinous rice. Perkin-Elmer System 2000 FTIR (equipped with DRIFT and PAS accessories) and System 2000 NIR FT-Raman spectrometers were used to collect spectra from ground samples of seven glutinous and 12 non-glutinous rice. When SIMCA (Soft Independent Modelling of Class Analogy) was used to classify raw spectral data, the best discrimination was achieved with the FT-Raman results followed by those from the PAS measurements. FT-Raman spectra of some samples of non-glutinous rice showed strong fluorescence effects. When these samples were excluded from analysis, modelling and classification improved.

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

Rapid identification of black peanut seeds by confocal micro-Raman and near-infrared FT-Raman spectroscopy

2014 ◽  
Vol 6 (8) ◽  
pp. 2537-2544 ◽  
Author(s):  
Xiao Wang ◽  
Hongxing Liu ◽  
Hanping Liu ◽  
Changchun Zeng
Keyword(s):  
Raman Spectroscopy ◽  
Near Infrared ◽  
Rapid Identification ◽  
Micro Raman Spectroscopy ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

Confocal micro-Raman spectroscopy and near-infrared (NIR) FT-Raman spectroscopy were used to analyse and identify cotyledons and the skins of black, white, red and ordinary pink peanut seeds.

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.

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