[13p-1F-3~18] 8.0 Plasma Electronics English Session

▲ [13p-1F-18] UV Absorption Spectroscopy for Absolute Concentration of RONS in Plasma Activated Water Treated by Atmospheric-Pressure Helium Plasma Jet

〇(PC)JunSeok Oh^1,2, Satsuki Ito¹, Maito Kakuta¹, Hiroshi Furuta^1,2, Akimitsu Hatta^1,2 (1.Kochi Univ. Technol., 2.Center Nanotechnol.)

Keywords:plasma-generated RONS,Plasma activated water,UV absorption

Plasma activated water (PAW) also referred to as plasma treated water (PTW) is gaining importance in recent research area at the Plasma Physics-Life Science interface. PAW is well known of bactericidal effect which to be extremely strong under acidic condition, especially below a critical pH value of 4.7. Since to solve the mechanisms, the correlation between the chemistry of PAW and the bactericidal effect was studied by a number of method such as electron spin resonance (ESR), ion chromatography, free radical scavenging activity, Fourier transform infrared spectroscopy (FTIR), and UV-Vis absorption spectroscopy. So far, many studies revealed that the presence of various reactive oxygen and nitrogen species (RONS) in PAW is strongly correlated to the bacterial inactivation and the studies also confirmed the long-term bactericidal activity.
We have used UV absorption spectroscopy to investigate RONS, especially long-living RONS in PAW. In recent, we have considered the absolute concentration of RONS which could be estimated by knowing absorptivity of standard reference solutions e.g. H₂O₂, NO₃⁻ and NO₂⁻. In this work, we discussed the absolute concentrations of the plasma-generated RONS for the results of our previous study of the production efficiency h of mm-jet and m-jet, presented at the spring meeting. In addition, we report recent our studies regarding influence of RONS generation on plasma exposure time and treatment distance.