Abstract
This study investigated the degradation of imidacloprid and fipronil in paddy water at pH 7 and pH 10. Both imidacloprid and fipronil degraded faster at pH 10, and fipronil degraded faster than imidacloprid at pH 10. The half-life estimates of imidacloprid were 182 and 44.7 days at pH 7 and pH 10, respectively, and those values of fipronil were 87.9 and 13.2 days, respectively. Fipronil sulfone was found in the degradation process of fipronil.