Corona Discharge and Field Electron Emission in Ambient Air Using a Sharp Metal Needle: Formation and Reactivity of CO3 -• and O2 -•

Kenzo Hiraoka; Stephanie Rankin-Turner; Satoshi Ninomiya; Haruo Shimada; Kazumasa Kinoshita; Shinichi Yamabe

doi:10.5702/massspectrometry.A0100

Corona Discharge and Field Electron Emission in Ambient Air Using a Sharp Metal Needle: Formation and Reactivity of CO₃ ^-• and O₂ ^-•

Mass Spectrom (Tokyo). 2021;10(1):A0100. doi: 10.5702/massspectrometry.A0100. Epub 2021 Dec 25.

Authors

Kenzo Hiraoka¹, Stephanie Rankin-Turner², Satoshi Ninomiya³, Haruo Shimada⁴, Kazumasa Kinoshita⁴, Shinichi Yamabe⁵

Affiliations

¹ Clean Energy Research Center, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
² W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA.
³ Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
⁴ Bio Chromato, Inc., 1-12-19 Honcho, Fujisawa, Kanagawa 251-0053, Japan.
⁵ Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan.

Abstract

CO₃ ^-• and O₂ ^-• are known to be strong oxidizing reagents in biological systems. CO₃ ^-• in particular can cause serious damage to DNA and proteins by H^• abstraction reactions. However, H^• abstraction of CO₃ ^-• in the gas phase has not yet been reported. In this work we report on gas-phase ion/molecule reactions of CO₃ ^-• and O₂ ^-• with various molecules. CO₃ ^-• was generated by the corona discharge of an O₂ reagent gas using a cylindrical tube ion source. O₂ ^-• was generated by the application of a 15 kHz high frequency voltage to a sharp needle in ambient air at the threshold voltage for the appearance of an ion signal. In the reactions of CO₃ ^-•, a decrease in signal intensities of CO₃ ^-• accompanied by the simultaneous increase of that of HCO₃ ^- was observed when organic compounds with H-C bond energies lower than ∼100 kcal mol^-1 such as n-hexane, cyclohexane, methanol, ethanol, 1-propanol, 2-propanol, and toluene were introduced into the ion source. This clearly indicates the occurrence of H^• abstraction. O₂ ^-• abstracts H⁺ from acid molecules such as formic, acetic, trifluoroacetic, nitric and amino acids. Gas-phase CO₃ ^-• may play a role as a strong oxidizing reagent as it does in the condensed phase. The major discharge product CO₃ ^-• in addition to O₂ ^-•, O₃, and NO _x ^• that are formed in ambient air may cause damage to biological systems.

Keywords: CO3−•; HCO3−; H• abstraction; O2−•; tunneling electron emission.