Flash-photolysis electron spin resonance in solution studies of free radicals

1984 ◽  
Vol 78 ◽  
pp. 257 ◽  
Author(s):  
Christopher D. Buckley ◽  
Andrew I. Grant ◽  
Keith A. McLauchlan ◽  
Andrew J. D. Ritchie
2011 ◽  
Vol 2011 ◽  
pp. 1-11
Author(s):  
Shinobu Ito ◽  
Tomohisa Mori ◽  
Hideko Kanazawa ◽  
Toshiko Sawaguchi

Electron spin resonance (ESR) method is a simple method for detecting various free radicals simultaneously and directly. However, ESR spin trap method is unsuited to analyze weak ESR signals in organs because of water-induced dielectric loss (WIDL). To minimize WIDL occurring in biotissues and to improve detection sensitivity to free radicals in tissues, ESR cuvette was modified and used with 5,5-dimethtyl-1-pyrroline N-oxide (DMPO). The tissue samples were mouse brain, hart, lung, liver, kidney, pancreas, muscle, skin, and whole blood, where various ESR spin adduct signals including DMPO-ascorbyl radical (AsA∗), DMPO-superoxide anion radical (OOH), and DMPO-hydrogen radical (H) signal were detected. Postmortem changes in DMPO-AsA∗and DMPO-OOH were observed in various tissues of mouse. The signal peak of spin adduct was monitored until the 205th day postmortem. DMPO-AsA∗in liver (y=113.8–40.7 log (day),R1=-0.779,R2=0.6,P<.001) was found to linearly decrease with the logarithm of postmortem duration days. Therefore, DMPO-AsA∗signal may be suitable for detecting an oxidation stress tracer from tissue in comparison with other spin adduct signal on ESR spin trap method.


1969 ◽  
Vol 47 (8) ◽  
pp. 1375-1379 ◽  
Author(s):  
Michie Shimizu ◽  
H. D. Gesser ◽  
M. Fujimoto

The electron spin resonance (e.s.r.) spectra of •CH3, •CHO, H and/or D, and possibly •CH2OH or •CH2OD were found by the ultraviolet (u.v.) photolysis of methanol —OH or —OD on porous high-silica glass at 77 °K. These e.s.r. spectra resemble the results of the u.v. photolysis of X-irradiated methanol indicating that some perturbation and/or sensitization occurred in the molecules by the glass surface. The absence of e.s.r. spectra from the same systems on the acid-leached glass, on the totally fluorinated glass, or on the totally —OH covered glass suggests that (i) the co-existence of surface contaminants, such as Al and Zr and not B, and some of surface —OH could be responsible for producing these free radicals, and (ii) the methanols adsorbed on these glass surfaces are stabilized against u.v. photolysis.


1982 ◽  
Vol 36 (1) ◽  
pp. 52-57 ◽  
Author(s):  
L. S. Singer ◽  
I. C. Lewis

The applications of electron spin resonance (ESR) to carbonaceous materials are reviewed. The stable paramagnetic species observed in the products of low-temperature pyrolysis are odd-alternate neutral free radicals, whereas the unpaired spins of higher temperature carbons and graphites are primarily conduction electrons. The variety of ESR properties and phenomena requires special attention to techniques of measurement and interpretations of results. The relevance to the carbonization process of the free radicals observed by ESR is also discussed.


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