Dissipation of captan in soil and tomato plants in field conditions

Abstract

Residues of captan in tomato plant and soil conditions were investigated. Nonsystemic phthalimide fungicide, captan was applied in pre-emergence at 1.5. 3 and 6 kg ha(-1). Soil and plant samples were collected at 4 h I day and 30 days after the application and analyzed for captan residues. A gas chromatographic method using aceytone, dichioromethane and petroleum ether as extraction solvents, was used to analyse residual captan. Captan residues were determined by gas chromatography-electron capture detection (GC-ECD), using an activated silica gel capillary column. The recovery of captan in soil and tomato was 83.7%. 84.4%, respectively. The concentration levels of captan residues in tomato field samples at the recommended preharvest interval were below the EU Codex and Turkish Food Codex established MRL values. The results showed that captan dissipation in soil and tomato coincided with C = 4.1628 e(-0.8959t), C = 2.0874 e(-0.4993t), the DT50 were about 2.1 and 2.6 d, respectively. The dissipation rate of captan in soil was faster than that of in tomato.