FT-Raman Spectroscopic Study of Decorated Stained Glass

1998 ◽  
Vol 52 (5) ◽  
pp. 679-682 ◽  
Author(s):  
H. G. M. Edwards ◽  
J. K. F. Tait

Two samples of decorated stained glass (14th century and 19th century) from Southwell Minster, Nottinghamshire, U.K. have been examined with the use of Fourier transform (FT)-Raman spectroscopy. The pigment used in both cases has been identified as red ochre, and the potential application of FT-Raman spectroscopy to an important area of conservation and restoration of glass artifacts is demonstrated.

2002 ◽  
Vol 34 (3) ◽  
pp. 259-266 ◽  
Author(s):  
L. F. C. de Oliveira ◽  
H. G. M. Edwards ◽  
J. C. Feo-Manga ◽  
M. R. D. Seaward ◽  
R. Lücking

AbstractThe first FT-Raman spectroscopic study of foliicolous lichens is reported. Detailed spectra obtained by macroscopic and microscopic means for Calenia triseptata Zahlbr., Echinoplaca strigulacea (Müll. Arg.) R.Sant. and Tricharia carnea (Müll. Arg.) R.Sant. collected from Costa Rican rainforests have been interpreted mainly in terms of their xalate content. The Raman spectra show a significant presence of calcium oxalate monohydrate (whewellite) despite the lack of calcium ions available in the leaf itself. A reasonable explanation for its presence could be the result of the incorporation of calcium ions from airborne dust and/or dissolved in rain falling on the canopy.


1992 ◽  
Vol 46 (10) ◽  
pp. 1503-1507 ◽  
Author(s):  
Y. Ozaki ◽  
R. Cho ◽  
K. Ikegaya ◽  
S. Muraishi ◽  
K. Kawauchi

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.


1989 ◽  
Vol 43 (5) ◽  
pp. 778-781 ◽  
Author(s):  
N. J. Everall ◽  
J. Howard

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.


2020 ◽  
Vol 32 (8) ◽  
pp. 1865-1868
Author(s):  
M. Chandra Sekhara Rao ◽  
R. Chenna Krishna Reddy ◽  
K.B. Chandra Sekhar ◽  
Y.V. Rami Reddy

A simple FT-Raman spectroscopic method was developed for identification of finasteride polymorph form in finished dosage form. Finasteride polymorph form I was used in the tablet preparation and the weight fraction of finasteride in tablet was only about 0.023. The method was successfully used to identify the polymorphic form of finasteride in tablet and also to detect up to a level of about 15% of the other polymorph of finasteride present in the solid dosage. The dosage form was characterized by different techniques i.e. powdered X-ray diffraction, infrared spectroscopy and Raman spectroscopy. Based on literature survey, only Raman spectroscopy method is able to identify the polymorph of finasteride in dosage form.


1992 ◽  
Vol 46 (10) ◽  
pp. 1540-1544 ◽  
Author(s):  
Catherine A. Butler ◽  
Ralph P. Cooney ◽  
William A. Denny

Amsacrine (4′-(9-acridinylamino)methanesulfon- m-anisidide) in both solid and aqueous forms was characterized with the use of resonance and nonresonance Raman spectroscopy (including FT-Raman spectroscopy). Evidence that the acridine nucleus is the dominant chromophoric unit contributing to the resonance Raman spectrum is based upon the apparent similarities of the spectra of aqueous amsacrine (in the unpro-tonated form) and acridine (in ethanol). The probable non-coplanarity of the acridine and phenyl units in the amsacrine molecule (based on previously reported crystal structure data) is consistent with the suggestion that the acridine nucleus may constitute an independent chromophoric unit. Further evidence is derived from analysis of the UV-visible spectrum, which indicates that excitation at 457.9 nm falls within an electronic transition of the acridine nucleus of amsacrine. The excitation profiles of aqueous amsacrine are presented, and four types of profiles have been identified.


2005 ◽  
Vol 70 (2) ◽  
pp. 168-177
Author(s):  
Zuzana Tománková ◽  
Pavel Matějka ◽  
Karel Volka ◽  
Vladimír Král

The potential of Fourier-transform (FT) Raman spectroscopy for verification of individual steps of synthesis of new chromatographic stationary phases was studied. 3-Aminopropylated silica gel was modified with two different optically active compounds ((+)-cloprostenol, (+)-(R)-2,2'-dihydroxy-1,1'-binaphthalene-3-carboxylic acid) via amide bonds. In the next step, free silanol groups were protected with trimethylsilyl groups. The FT Raman spectroscopic results compared with the data obtained by elemental analysis enable not only qualitative verification of synthetic steps, but also a semiquantitative determination of covering of the silica gel surface by derivatization agent.


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