In-situ UV Absorption Spectroscopy for Observing Dissolved Ozone in Water

Oh, Jun‐Seok; Yajima, Hideki; Hashida, Keiya; Ono, Taizo; Ishijima, Tatsuo; Serizawa, Izumi; Furuta, Hiroshi; Hatta, Akimitsu

doi:10.2494/photopolymer.29.427

Cited by 22 publications

(14 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among the reactive species, ozone (O 3 ) and chlorine species (Cl 2 − , OCl − ) are good candidates since they are both generated by cold atmospheric plasmas and their lifetime in liquids is in the range of seconds to hours, depending on the nature of the liquid [87][88][89]. We attempted to detect ozone production in PAP by two spectroscopic methods: directly by its UV absorption at 258-260 nm [90] and indirectly by the absorption detection at 600 nm of the decolorization of potassium indigo trisulfonate dye by ozone [91]. Both methods failed since the high production of H 2 O 2 and NO 2 − also generates a peak at 258-260 nm and these two compounds together react with potassium indigo trisulfonate.…”

Section: Characterization Of Transient Reactive Species Present In Papmentioning

confidence: 99%

Role of Short- and Long-Lived Reactive Species on the Selectivity and Anti-Cancer Action of Plasma Treatment In Vitro

Sklias

Sousa

Girard

2021

Cancers

View full text Add to dashboard Cite

(1) Plasma-activated liquids (PAL) have been extensively studied for their anti-cancer properties. Two treatment modalities can be applied to the cells, direct and indirect plasma treatments, which differ by the environment to which the cells are exposed. For direct plasma treatment, the cells covered by a liquid are present during the plasma treatment time (phase I, plasma ON) and the incubation time (phase II, plasma OFF), while for indirect plasma treatment, phase I is cell-free and cells are only exposed to PAL during phase II. The scope of this work was to study these two treatment modalities to bring new insights into the potential use of PAL for cancer treatment. (2) We used two models of head and neck cancer cells, CAL27 and FaDu, and three models of normal cells (1Br3, NHK, and RPE-hTERT). PBS was used as the liquid of interest, and the concentration of plasma-induced H2O2, NO2− and NO3−, as well as pH change, were measured. Cells were exposed to direct plasma treatment, indirect plasma treatment or reconstituted buffer (PBS adjusted with plasma-induced concentrations of H2O2, NO2−, NO3− and pH). Metabolic cell activity, cell viability, lipid peroxidation, intracellular ROS production and caspase 3/7 induction were quantified. (3) If we showed that direct plasma treatment is slightly more efficient than indirect plasma treatment and reconstituted buffer at inducing lipid peroxidation, intracellular increase of ROS and cancer cell death in tumor cells, our data also revealed that reconstituted buffer is equivalent to indirect plasma treatment. In contrast, normal cells are quite insensitive to these two last treatment modalities. However, they are extremely sensitive to direct plasma treatment. Indeed, we found that phase I and phase II act in synergy to trigger cell death in normal cells and are additive concerning tumor cell death. Our data also highlight the presence in plasma-treated PBS of yet unidentified short-lived reactive species that contribute to cell death. (4) In this study, we provide strong evidence that, in vitro, the concentration of RONS (H2O2, NO2− and NO3−) in combination with the acidic pH are the main drivers of plasma-induced PBS toxicity in tumor cells but not in normal cells, which makes ad hoc reconstituted solutions powerful anti-tumor treatments. In marked contrast, direct plasma treatment is deleterious for normal cells in vitro and should be avoided. Based on our results, we discuss the limitations to the use of PAL for cancer treatments.

show abstract

Section: Characterization Of Transient Reactive Species Present In Papmentioning

confidence: 99%

Role of Short- and Long-Lived Reactive Species on the Selectivity and Anti-Cancer Action of Plasma Treatment In Vitro

Sklias

Sousa

Girard

2021

Cancers

View full text Add to dashboard Cite

show abstract

“…In order to measure the real-time changes in the concentrations of O2 (aq) and RONS species in DI water during the plasma jet treatment, we developed a UV-Vis spectroscopy (UV-Vis) method. 9,[21][22][23][24][25] We have shown in a previous study, UV-Vis spectroscopy can be used to accurately determine the concentrations of H2O2, NO2 and NO3 in reference solutions, with mixed concentrations of these molecules, even with varying O2(aq) tension levels. 9) Two important observations from the initial and follow-up studies were that (1) the choice of He or Ar process gas influences the resultant RONS chemistry generated by the plasma jet, 9) and (2) both He and Ar plasma jets de-oxygenate DI water.…”

Section: Introductionmentioning

confidence: 99%

Modulating the concentrations of reactive oxygen and nitrogen species and oxygen in water with helium and argon gas and plasma jets

Ogawa

Gaur

et al. 2018

Jpn. J. Appl. Phys.

Self Cite

View full text Add to dashboard Cite

We employed UV–vis spectroscopy to monitor real-time changes in the oxygen tension and concentration of reactive oxygen and nitrogen species (RONS) in deionized (DI) water during treatments with helium (He) and argon (Ar) gas plasma jets. He and Ar gas jets are both shown to de-oxygenate DI water with He being more efficient than Ar, whilst the plasma jets deliver and regulate the concentrations of hydrogen peroxide (H2O2), nitrite (NO2−) and nitrate (NO3−) in DI water. The H2O2 and NO3− production efficiency varied between He and Ar plasma jets, but was similar for NO2−. Whilst DI water fully equilibrated with ambient air prior to treatment (de-oxygenated by both plasma jets) when DI water was first de-oxygenated by an inert gas jet treatment, both plasma jets were found to be capable of oxygenating DI water. These insights were then used to show how different combinations of plasma jet and inert gas jet treatments can be used to modulate O2 tension and RONS chemistry. Finally, potential further improvements to improve control in the use of plasma jets in regulating O2 and RONS are discussed.

show abstract

“…These equations are possible reactions of aqueous plasma generating reactive oxygen species with water and other oxygen species. In theory, plasma generates different reactive species: O 2 can generate reactive oxygen species, while air can generate both reactive oxygen species and reactive nitrogen species [9].…”

Section: Resultsmentioning

confidence: 99%

“…It is known that ozone has a maximum absorption at the wavelength of 260 nm and the nitrogen oxides at 205 nm [9]. The absorbance values for 260 and 205 nm wavelengths were determined both in diluted samples (1:200) in the time interval between 30 seconds and 60 minutes (Fig.…”

Section: Fig 1 Variation Of Ozone Concentration In Timementioning

confidence: 99%

See 1 more Smart Citation

UV absorption spectra, Iodometric determination and pH variation in ozonated water using ozone generator

Dincă

Ferdeş

Zabava

et al. 2018

Engineering for Rural Development

View full text Add to dashboard Cite

Abstract. An UV absorption spectroscopy technique for real time detecting of reactive ozone and nitrogen oxides species in ozonated water was compared with the traditional iodometric method. The UV absorption spectra are important for understanding the composition of ozonated water. A commercially available ozone generator was used to obtain ozonated water by the bubbling method. A volume of 200 ml of distilled water was treated with the gaseous mixture resulted from the ozone generator. The UV absorption spectra were recorded between 200-300 nm and the ozone concentration wasdetermined by the iodometric method. The results showed the presence of some characteristic peaks for nitrogen oxides and ozonespecies in the UV absorption spectra, the values of the absorbance increasing in time. It has been shown that, due to the high nitrogen content in the air passed through the corona discharge, nitrogen oxides are mainly produced and less ozone. This could explain also the strong decrease of the pH values, after one hour of water ozonation. The iodometric analysis method showed the synthesis of some agents with strong oxidative potential, which can be both ozone and nitrogen oxides. The water sample treated for one hour with the ozone generator was analysed again after one week and one month, the results showing that reactive oxidizing species were kept also after this time. The UV absorption spectra, concentration of ozone (g·l -1 ) determined by the traditional iodometric method and evolution of the pH values were assessed.

show abstract

In-situ UV Absorption Spectroscopy for Observing Dissolved Ozone in Water

Cited by 22 publications

References 13 publications

Role of Short- and Long-Lived Reactive Species on the Selectivity and Anti-Cancer Action of Plasma Treatment In Vitro

Role of Short- and Long-Lived Reactive Species on the Selectivity and Anti-Cancer Action of Plasma Treatment In Vitro

Modulating the concentrations of reactive oxygen and nitrogen species and oxygen in water with helium and argon gas and plasma jets

UV absorption spectra, Iodometric determination and pH variation in ozonated water using ozone generator

Contact Info

Product

Resources

About