Degradation kinetics of carbofuran insecticide in tomato fruits

Abstract

The degradation rate and kinetic parameters of carbofuran insecticide in tomato fruits were calculated. The degradation of carbofuran was found to follow first-order reaction kinetics. The rate constants for carbofuran were 0.082 day-1 and 0.073 day-1 for the recommended application rate (10 kg feddan-1) and for the application rate used by farmers (13.5 kg feddan-1) respectively. The half-life time (t1/2) values for the recommended application rate and for the application rate used by farmers were 8.45 days and 9.50 days, respectively. The safe application time of carbofuran insecticide for the recommended application rate and for the application rate used by farmers were after 28 days and after 35 days , respectively. Spectrophotometry was employed to determine the carbofuran residues in tomato fruits, with a limit of detection (LOD) of 0.039 ppm and percent recovery in the range from 92.87 to 95.54%