Dielectric barrier discharge (DBD) plasma induced flavonoid degradation kinetics and mechanism in water

Abstract

In this work, we evaluated the degradation mechanism of standard flavonoids when treated with dielectric barrier discharge (DBD) plasma in water. Five different standard flavonoids were chosen for analysis, including apigenin, myricetin, kaempferol, rutin, and quercetin. All flavonoids were treated for 5 min, and the samples were collected at different time intervals. The degradation kinetics of DBD plasma-treated samples were analyzed using HPLC, which follows first-order reaction kinetics. Various degradation peaks were observed in the HPLC chromatogram that started appearing within 10 s of DBD plasma treatment and increased until 60 s–90 s, subsequently degraded completely within 5 min of plasma treatment. LC-MS analysis was performed for the quercetin fragments obtained at 7.54 min. Based on the obtained major molecular ion peak at m/z 152.98 And 196.96; a quercetin degradation mechanism is suggested. The effect of two different feed gases (clean dry air and N2) on flavonoid degradation was also evaluated.