The Hydroxyl Radical is a Critical Intermediate in the Voltammetric Detection of Hydrogen Peroxide

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• 作者：James G. Roberts ; Maxim A. Voinov ; Andreas C. Schmidt ; Tatyana I. Smirnova ; Leslie A. Sombers
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：March 2, 2016
• 年：2016
• 卷：138
• 期：8
• 页码：2516-2519
• 全文大小：339K
• ISSN：1520-5126

文摘

Cyclic voltammetry is a widely used and powerful tool for sensitively and selectively measuring hydrogen peroxide (H₂O₂). Herein, voltammetry was combined with electron paramagnetic resonance spectroscopy to identify and define the role of an oxygen-centered radical liberated during the oxidation of H₂O₂. The spin-trap reagents, 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and 2-ethoxycarbonyl-2-methyl-3,4-dihydro-2H-pyrrole-1-oxide (EMPO), were employed. Spectra exhibit distinct hyperfine patterns that clearly identify the DMPO^•–OH and EMPO^•–OH adducts. Multiple linear regression analysis of voltammograms demonstrated that the hydroxyl radical is a principal contributor to the voltammetry of H₂O₂, as signal is attenuated when this species is trapped. These data incorporate a missing, fundamental element to our knowledge of the mechanisms that underlie H₂O₂ electrochemistry.