EPR study of light illumination effects on radicals in gamma-irradiated l-alanine
| ISSN: | 1386-1425 |
|---|---|
| DOI: | 10.1016/j.saa.2003.10.030 |
| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d1de6e661c6b2bd9859296aea175e358 https://doi.org/10.1016/j.saa.2003.10.030 |
| Rights: | CLOSED |
| Přírůstkové číslo: | edsair.doi.dedup.....d1de6e661c6b2bd9859296aea175e358 |
| Autor: | K. Schultka, Einar Sagstuen, M. Penkowski, Bartlomiej Ciesielski |
| Rok vydání: | 2004 |
| Předmět: |
Time Factors
Free Radicals Light Radical Population Photochemistry Analytical Chemistry law.invention Ionizing radiation law Irradiation Microwaves Electron paramagnetic resonance education Instrumentation Lighting Spectroscopy Fluorescent lamp education.field_of_study Alanine Dosimeter Chemistry Electron Spin Resonance Spectroscopy Temperature Gamma ray Dose-Response Relationship Radiation Atomic and Molecular Physics and Optics Gamma Rays Sunlight Powders |
| Zdroj: | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 60:1327-1333 |
| ISSN: | 1386-1425 |
| DOI: | 10.1016/j.saa.2003.10.030 |
| Popis: | Exposure of gamma-irradiated L-alanine samples to sunlight and to light from a regular, fluorescent lamp resulted in significant changes in their EPR resonance patterns, both to spectral shapes and intensities. The experimental EPR spectra were numerically decomposed into three components reflecting contributions of three different radicals (R1-R3) generated by ionizing radiation in alanine. The light exposure caused a decay of the measured EPR signal intensity. For similar light intensities and exposure times the decay was much more pronounced in samples illuminated by sunlight than in samples illuminated by the fluorescent lamp. In both cases light-induced decay of R1 radicals was observed. Sunlight illumination resulted in a moderate decay of R2 radicals and in a doubling of the R3 radical population. On the other hand, fluorescent light caused a significant increase of R2 radicals and did not change the amount of R3 radicals. A quantitative analysis of the variations of the three radical contributions to the total EPR spectra upon fluorescent light exposure suggests a net R1-->R2 free radical transformation. These effects of light on the alanine dosimetric signal should be taken into account in dosimetry protocols, assuring protection of alanine dosimeters from extended exposure to light. |
| Databáze: | OpenAIRE |
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