author(s)
Sushil Ahlawat, Savita Rani and Reena Chauhan

abstract
Present study was designed to determine the dissipation behavior of different insecticides viz., 20% EC chlorpyriphos 300 g, 50% EC ethion 500 g and 25% EC quinalphos 250 g a.i. ha-1 in tomato and green pea. The commercial formulation of each insecticide was sprayed on both the vegetable crops. The collected fruit and soil samples were extracted and cleaned up by using latest QuEChERS technique, further processed by column chromatography. The insecticide residues in fruits and soil were estimated by gas chromatography (GC) and confirmed by gas chromatography-mass spectrometry (GC-MS/MS). Half life period for chlorpyriphos, ethion and quinalphos in tomato was found 2.37, 1.64 and 2.37 days and in green pea 2.83, 2.89 and 4.42 days at the recommended dose, respectively. Residue of no insecticide except ethion (0.067 mg kg-1 soil) was found in soil at harvest. In tomato samples, all the three pesticides dissipated at a faster rate than that of green pea samples.