Abstract
Quantification of hydroxyl radical concentration using two chemical probes was assessed through the Fenton reaction. The probes were 1,2-benzopyrone (coumarin) for fluorescence and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) for electron spin resonance (ESR). The corresponding hydroxylated species, namely 7-hydroxycoumarin (7HC) and 2-hydroxy-5,5-dimethyl-1-pyrroline-N-oxide (DMPO-OH adduct), were monitored by fluorescence and ESR-spin trapping techniques, respectively. The experiments were designed according to the theoretical conditions determined for stable fluorescence and EPR signals. The results demonstrate that: the optimal [chemical probe]:[H2O2] ratio predicted by a simplified quasi-steady-state model was in good agreement with the optimal [chemical probe]:[H2O2] ratio observed experimentally for [H2O2]:[Fe2+] = 10, and the proper adjustment of the [chemical probe]:[H2O2] ratio at a given concentration of the Fenton's reagent improves the detected amount of hydroxyl radicals. Finally, using DMPO required a higher concentration compared to coumarin to yield the same amount of OH detected but resulted in a more reliable probe for detecting OH under the consideration of this study.
Original language | English |
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Pages (from-to) | 5321-5330 |
Number of pages | 10 |
Journal | RSC Advances |
Volume | 8 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2018 |
Externally published | Yes |
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering