Indexed on: 03 Feb '07Published on: 03 Feb '07Published in: Environmental Monitoring and Assessment
Presence of pesticide residues was studied in rain water during 2002 employing multi residue analysis method by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns. The presence of pesticide residues in surface aquatic system triggered the investigation of the presence of pesticides in rain water. A total of 13 pesticides were detected in rain water samples. Among the different groups of pesticides, organochlorines were present in the range of 0.041-7.060 ppb with maximum concentration of p,p'-DDT up to 7.060 microg l(-1). Synthetic pyrethroids were present ranging from 0.100 to 1.000 microg l(-1) and organophosphates in the range of 0.050-4.000 microg l(-1) showing maximum contamination with cypermethrin (1.000 microg l(-1)) and monocrotophos (4.000 microg l(-1)) of the respective groups. Almost 80% samples showed the residues above MRL of 0.5 ppb fixed for multi residues and on the basis of single pesticide, 16-50% samples contained residues above the MRL value of 0.1 ppb.