Dissipation of Fungicides, Insecticides, and Acaricide in Tomato Using HPLC-DAD and QuEChERS Methodology

Excessive use of pesticides in tomato cultivation could lead to impact on environment and health. Here, dissipation rate of six widely used pesticides in growing tomatoes, namely, chlorothalonil, pymetrozine, metalaxyl-m, metalaxyl, abamectin, and propamocarb hydrochloride, was evaluated. Tomato samples were collected within 2 weeks after pesticides application, and the pesticide residues extracted by an optimized QuEChERS method and quantified by high-performance liquid chromatography combined with diode array detection. The half-life of these pesticides was found to be 2.06, 1.65, 19.8, 4.88, 1.06, and 1.29 days for chlorothalonil, pymetrozine, metalaxyl-m, metalaxyl, abamectin, and propamocarb hydrochloride, respectively. Preharvest intervals (PHI) for these pesticides ranged from 3 to 9 days, with the longest being for metalaxyl (9 days), followed by chlorothalonil and abamectin (6 days). Pymetrozine metalaxyl-m, and propamocarb hydrochloride had PHIs of 3, 4, and 4 days, respectively. Due to the immediate consumption of the tomatoes after harvest, the persistence of metalaxyl, chlorothalonil, and abamectin in the environment is expected to have an adverse health effect.