Sensitive algorithm for multiple-excitation-wavelength resonance Raman spectroscopy

2014 ◽  
Author(s):  
Balakishore Yellampalle ◽  
Hai-Shan Wu ◽  
William McCormick ◽  
Mikhail Sluch ◽  
Robert Martin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Excitation Wavelength

scholarly journals Rapid Raman Spectroscopic Analysis of Stress Induced Degradation of the Pharmaceutical Drug Tetracycline

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1866 ◽  
Author(s):  
Christian Domes ◽  
Timea Frosch ◽  
Juergen Popp ◽  
Torsten Frosch
Keyword(s):  
Raman Spectroscopy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Pharmaceutical Products ◽  
Small Sample ◽  
Small Concentration ◽  
Stress Factors ◽  
Excitation Wavelength ◽  
Raman Spectroscopic ◽  
Concentration Changes

Stress factors caused by inadequate storage can induce the unwanted degradation of active compounds in pharmaceutical formulations. Resonance Raman spectroscopy is presented as an analytical tool for rapid monitoring of small concentration changes of tetracycline and the metabolite 4˗epianhydrotetracycline. These degradation processes were experimentally induced by changes in temperature, humidity, and irradiation with visible light over a time period of up to 23 days. The excitation wavelength λexc = 413 nm was proven to provide short acquisition times for the simultaneous Raman spectroscopic detection of the degradation of tetracycline and production of its impurity in small sample volumes. Small concentration changes could be detected (down to 1.4% for tetracycline and 0.3% for 4-epianhydrotetracycline), which shows the potential of resonance Raman spectroscopy for analyzing the decomposition of pharmaceutical products.

Application of UV-Vis and resonance Raman spectroscopy to study bleaching and photoyellowing of thermomechanical pulps

Holzforschung ◽  
2006 ◽  
Vol 60 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Anna-Stiina Jääskeläinen ◽  
Anna-Maija Saariaho ◽  
Jouko Vyörykkä ◽  
Tapani Vuorinen ◽  
Pavel Matousek ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Light Exposure ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Excitation Wavelength ◽  
Thermomechanical Pulp ◽  
Pulp Bleaching ◽  
Absorption Bands ◽  
Peroxide Bleaching ◽  
Brightness Reversion

Abstract The chemistry of thermomechanical pulp bleaching and brightness reversion was studied. First, UV-Vis reflectance spectroscopy was used to obtain information on the reactive structures in pulp. Based on these data, a Raman excitation wavelength was chosen close to the absorption bands of the chromophores formed to take advantage of the resonance enhancement (resonance Raman spectroscopy). Fluorescence was rejected with a picosecond Kerr gate. The results revealed that coniferyl aldehyde structures were partly removed by alkaline peroxide bleaching and these structures were further degraded during light exposure. However, this reaction was obviously not responsible for chromophore formation in the pulp. On the other hand, based on the resonance Raman spectra, formation of quinonoid structures, possibly para-quinones, was a more prominent explanation for the brightness reversion.

scholarly journals Structure of the retinal chromophore in sensory rhodopsin I from resonance Raman spectroscopy

1989 ◽  
Vol 264 (31) ◽  
pp. 18280-18283
Author(s):  
S P Fodor ◽  
R Gebhard ◽  
J Lugtenburg ◽  
R A Bogomolni ◽  
R A Mathies
Keyword(s):  
Raman Spectroscopy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Sensory Rhodopsin ◽  
Retinal Chromophore ◽  
Sensory Rhodopsin I
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