DETERMINATION OF MULTIPLE PESTICIDE RESIDUES IN COUNTRY BEAN COLLECTED FROM SUPERVISED FIELD TRIAL

Abstract

The study was conducted to detect and quantify the residue of quinalphos, chloropyrifos, fenitrothion and diazinon in country bean and to compare the detected residues with the Maximum Residue Limit (MRL) using Quick, Easy, Cheap, Effective, Rugged and Safe extraction technique and Gas Chromatography coupled with Flame Thermionized Detector. A supervised field trial was undertaken sprayed with the field dose (1.5 ml/L of water) of all of the selected insecticides. Samples were collected at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 12 days after spray. The residue of quinalphos was detected upto 9 DAS, of which the level of residue was above MRL at 8 DAS. The quinalphos residue remained 0.009 mg/kg at 9 DAS, which was below MRL. Therefore, the Pre-Harvest Interval (PHI) for quinalphos was set at 9 DAS and no residue was detected at 10 DAS. The residue of chloropyrifos was detected upto 8 DAS, of which the level of residue was above MRL at 6 DAS. The chlorpyrifos residue remained 0.044 mg/kg at 7 DAS, which was below MRL. So, the Pre-Harvest Interval (PHI) for chlorpyrifos was set at 7 DAS and no residue was detected at 9 DAS. The residue of fenitrothion was detected upto 8 DAS, of which the level of residue was above MRL at 7 DAS. The fenitrothion residue remained 0.007 mg/kg at 8 DAS, which was below MRL. So, the Pre-Harvest Interval (PHI) for fenitrothion was set at 8 DAS and no residue was detected at 9 DAS. The residue of diazinon was detected upto 9 DAS, of which the level of residue was above MRL at 8 DAS. The residue of diazinon remained 0.007 mg/kg at 9 DAS, which was below MRL. So, the Pre-Harvest Interval (PHI) for diazinon was set at 9 DAS and no residue was detected at 10 DAS.