Degradation of carbendazim in aqueous solution by dielectric barrier discharge cold plasma: Identification and toxicity of degradation products

Abstract

Dielectric barrier discharge (DBD) cold plasma, as a new nonthermal technology, has attracted increasing attention in pesticide degradation. In this study, DBD plasma was used to degrade carbendazim (MBC) in aqueous solution. Under the optimal conditions (160 kv, 50 Hz), MBC solution (0.5 μg/mL) was degraded by 89.04% after plasma treatment for 10 min. Four MBC degradation products were identified, one of which was a common oxidative degradation product (5-hydroxycarbendazim, m/z 208.07); the others were identified (m/z 118.06, m/z 132.08 and m/z 104.05) to have formed by the cleavage of the benzimidazole heterocyclic ring. The degradation pathways were obtained by analysis of degradation products at different treatment times. The toxicity of the degradation products was estimated based on the survival rate of yeast, indicating much lower toxicity levels compared to that of MBC. This study provides a theoretical basis for the application of DBD plasma in the degradation of benzimidazole pesticides in foods.