fig5

Figure 5. (A) Quenching experiment; EPR spectra of (B) ^•OH and SO₄^•-, (C) ¹O₂, and (D) O₂^•-. Experimental conditions: [EtOH] = [TBA] = 200 mM, [L-His] = [p-BQ] = 0.5 mM, [KI] = 1 mM, [DMPO] = [TEMP] = 10 mM, [CBZ] = 20 mg/L, [Cat.] = 0.10 g/L, [PMS] = 0.30 g/L, initial pH = 6.38. Each experiment was performed in triplicate, with error bars indicating the standard deviation of the results. EtOH: Ethanol; TBA: tert-butanol; L-His: L-histidine; p-BQ: para-benzoquinone; KI: potassium iodide; DMPO: 5,5-Dimethyl-1-pyrroline N-oxide; TEMP: 2,2,6,6-Tetramethylpiperidine; CBZ: carbamazepine; Cat.: catalyst; PMS: peroxymonosulfate; EPR: electron paramagnetic resonance; ^•OH: hydroxyl radical; SO₄^•-: sulfate radical; ¹O₂: singlet oxygen; O₂^•-: superoxide radical.