Analysis of short-lived reactive species in gas-liquid interfacial plasma with high-speed liquid column flow

Gas-liquid interfacial plasmas (GLIPs) have been of great interest and have been widely applied. For medical and agricultural applications, it is necessary to control the reactive species produced by GLIPs, and it is especially important to understand the behavior of short-lived reactive species. In this study, we have developed a GLIP system with a high-speed liquid column flow to measure the spatio-temporal distribution of short-lived reactive species in the order of msec [1]. Using this system, we have succeeded in experimentally measuring the fast decay of OH radicals and analyzing their decay times using a numerical model that takes surface localization into account. Furthermore, we are trying to measure not only OH radicals but also short-lived reactive nitrogen species. We have successfully measured the time decay of precursors of reactive nitrogen species by using the reagent p-HPA (p-hydroxyphenylacetic acid), which is a scavenger of nitrite and nitrate precursors. The results, such as the fact that only the precursor of nitrite decayed with time, led to the conclusion that the precursor of the reactive nitrogen species detected in the present study was N₂O₃.