Effects of chlorine, hydrogen peroxide, and ozone on the reduction of mancozeb residues on tomatoes

In this study, the effects of widely used oxidizers (chlorine, hydrogen peroxide, and ozone) on the reduction of mancozeb residues on tomatoes were investigated. Mature tomato samples grown in a greenhouse were treated with mancozeb and collected at different time intervals. Mancozeb residue levels in the samples were determined for each interval using a gas chromatographymass spectrometry method. A group of the samples with a residue level of approximately 3 mg kg^–1 was selected for dipping solutions experiments. Selected samples were dipped into the chlorine (10 and 100 mg L^–1), hydrogen peroxide (10 and 100 mg L^–1), and ozone (1 and 3 mg L^–1) solutions for 5, 10, 15, and 20 min. After each experiment, the residues on the samples were analyzed and percent reductions were calculated. The reductions in residual mancozeb were significantly (P 0.05) influenced by dipping into the chlorine, hydrogen peroxide, and ozone solutions as compared to water. The results show that the most effective treatment for the reduction of mancozeb residues from the tomatoes was dipping into the chlorine solution at 100 mg L^–1 for 20 min.