Non-Thermal Plasma in Contact with Water: The Origin of Species

TY - JOUR

T1 - Non-Thermal Plasma in Contact with Water

T2 - The Origin of Species

AU - Gorbanev, Yury

AU - O'Connell, Deborah

AU - Chechik, Victor

N1 - © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.This content is made available by the publisher under a Creative Commons Attribution Licence. This means that a user may copy, distribute and display the resource providing that they give credit. Users must adhere to the terms of the licence.

PY - 2016/2/24

Y1 - 2016/2/24

N2 - Non-thermal atmospheric pressure plasma has attracted considerable attention in recent years due to its potential for biomedical applications. Determining the mechanism of the formation of reactive species in liquid treated with plasma is thus of paramount importance for both fundamental and applied research. In this work, the origin of reactive species in plasma-treated aqueous solutions was investigated by using spin-trapping, hydrogen and oxygen isotopic labelling and electron paramagnetic resonance (EPR) spectroscopy. The species originating from molecules in the liquid phase and those introduced with the feed gas were differentiated by EPR and 1H NMR analysis of liquid samples. The effects of water vapour and oxygen admixtures in the feed gas were investigated. All the reactive species detected in the liquid samples were shown to be formed largely in the plasma gas phase. It is suggested that hydrogen peroxide (determined by UV/Vis analysis) is formed primarily in the plasma tube, whereas the radical species ·OOH, ·OH and ·H are proposed to originate from the region between the plasma nozzle and the liquid sample.

AB - Non-thermal atmospheric pressure plasma has attracted considerable attention in recent years due to its potential for biomedical applications. Determining the mechanism of the formation of reactive species in liquid treated with plasma is thus of paramount importance for both fundamental and applied research. In this work, the origin of reactive species in plasma-treated aqueous solutions was investigated by using spin-trapping, hydrogen and oxygen isotopic labelling and electron paramagnetic resonance (EPR) spectroscopy. The species originating from molecules in the liquid phase and those introduced with the feed gas were differentiated by EPR and 1H NMR analysis of liquid samples. The effects of water vapour and oxygen admixtures in the feed gas were investigated. All the reactive species detected in the liquid samples were shown to be formed largely in the plasma gas phase. It is suggested that hydrogen peroxide (determined by UV/Vis analysis) is formed primarily in the plasma tube, whereas the radical species ·OOH, ·OH and ·H are proposed to originate from the region between the plasma nozzle and the liquid sample.

KW - EPR spectroscopy

KW - isotopic labelling

KW - plasma chemistry

KW - radicals

KW - reactive oxygen species

UR - http://www.scopus.com/inward/record.url?scp=84959255807&partnerID=8YFLogxK

U2 - 10.1002/chem.201503771

DO - 10.1002/chem.201503771

M3 - Article

C2 - 26833560

SN - 0947-6539

VL - 22

SP - 3496

EP - 3505

JO - Chemistry : A European Journal

JF - Chemistry : A European Journal

IS - 10

ER -