Dimethylnitrosamine Detection and Measurement Using Laser Raman Spectroscopy

1977 ◽  
Vol 31 (6) ◽  
pp. 515-518 ◽  
Author(s):  
Dwaine M. Thomas
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
Signal Response

The Raman spectra of various concentrations of dimethylnitrosamine in water have been measured. The lowest concentration detected was 10 mg/l. Instrumental parameters were varied to optimize the signal response.

Raman Addition Spectroscopy with a Rotating Cell

1975 ◽  
Vol 29 (5) ◽  
pp. 386-389 ◽  
Author(s):  
Arthur K. Covington ◽  
Jennifer M. Thain
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Relative Intensity ◽  
Internal Standard ◽  
Laser Raman Spectroscopy ◽  
New Technique ◽  
Reference Substance ◽  
Laser Raman ◽  
Intensity Measurements ◽  
A New Technique

A new technique is described for obtaining quantitative relative intensity measurements, in the study of solution equilibria by laser-Raman spectroscopy, without the necessity for adding an internal standard to the sample. A rotating cylindrical double cell with separate compartments for sample and reference is used to superimpose the Raman spectra of sample and reference and hence avoid any uncertainties arising from the displacement of the equilibrium by reference substance addition.

Raman spectroscopy and electrochemistry of water-soluble porphyrins at a silver electrode

1990 ◽  
Vol 68 (5) ◽  
pp. 787-790 ◽  
Author(s):  
Hideo Orita ◽  
Masao Shimizu ◽  
Chizuko Nishihara ◽  
Takashi Hayakawa ◽  
Katsuomi Takehira
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Metal Cations ◽  
Silver Electrode ◽  
Water Soluble ◽  
Laser Raman Spectroscopy ◽  
Cyclic Voltammograms ◽  
Porphyrin Ring ◽  
Laser Raman

Cyclic voltammetry and laser Raman spectroscopy were applied to investigate insitu the properties and structures of metal meso-tetrakis (p-sulfonatophenyl)porphyrins (MeTPPS, Me = Co, Fe, Mn, Cu, Ni) adsorbed on a silver electrode in 0.05 M H2SO4 aqueous solution. The cyclic voltammograms for O2 reduction were investigated by changing the metal cations in the porphyrin ring. Among the porphyrins examined, only CoTPPS shows catalytic behavior for O2 electrochemical reduction. The Raman spectra of MeTPPS in aqueous solution are very similar to those of metal tetraphenylporphyrins (MeTPP), and the band assignments were carried out on the basis of the results for [FeTPP]2O. The Raman spectra of MeTPPS on a silver electrode were measured under a N2 or O2 atmosphere, changing the applied potentials and the metal cations in the porphyrin ring. Their spectra are very sensitive to metal cations, but not so to applied potential. Keywords: porphyrin, SERS, electrochemistry, dioxygen, silver electrode.

Theoretical Fitting of Computer Processed Laser Raman Spectra from Methane- and Propane-Air Flames

1979 ◽  
Vol 33 (1) ◽  
pp. 41-45 ◽  
Author(s):  
David A. Stephenson ◽  
Richard J. Blint
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Computer Processing ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
Rapid Acquisition ◽  
Laser Raman Spectra ◽  
Premixed Laminar ◽  
Primary Measure

A technique for rapid acquisition and computer processing of Raman signals is described for probing premixed laminar hydrocarbon-air flames using laser Raman spectroscopy. Temperatures can be determined to within ±50°K by fitting the observed N2 spectrum at any point in the flame. Fits to the spectra of O2, CO, H2, and CO2 are used to measure their mole fractions at the calculated N2 temperature. For the remaining polyatomic species, the total area under the peak is the primary measure of their concentration.

Azo Dye Tautomeric Structures Determined by Laser-Raman Spectroscopy

1977 ◽  
Vol 31 (1) ◽  
pp. 30-35 ◽  
Author(s):  
P. J. Trotter
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Azo Dye ◽  
Laser Raman Spectroscopy ◽  
Acidic Media ◽  
Keto Form ◽  
Laser Raman ◽  
Aqueous Acid ◽  
Tautomeric Forms

Raman spectra of a number of azo dye structures have been analyzed. In azonaphthol and azopyrazol dyes, hydroxyazo to keto-hydrazone tautomerizations, [Formula: see text] were observed in aqueous basic and acidic media. Observations of azo and ring vibrations, as well as hydrazone (C=N plus C=0) bands, were made. It was noted that the azo-anions (examined at pH 12) convert to the protonated neutral hydrazone (keto) form in aqueous acid (run at pH 2). Infrared spectra were used to confirm the presence of the C=0 group in keto-tautomeric forms.

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