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.
Description:
A Thesis
Submitted to the Department of Entomology
Sher-e-Bangla Agricultural University, Dhaka, in partial
fulfillment of the requirements
for the degree
of
MASTER OF SCIENCE
IN
ENTOMOLOGY
SEMESTER: JULY-DECEMBER, 2015