Determination of insecticide residues in groundwater of Mardan Division, NWFP Pakistan: A case study

Insecticide residue values in groundwater samples from Mardan Division, Nor th-Western Frontier Province, Pakistan, are reported in this paper. The sam ples were extracted with dichloromethane and analysed on a gas chromatograp h equipped with an electron capture detector (ECD-Ni-63) using a capillary column. Contamination levels in all sites were found to be below the maximu m acceptable concentration (MAC) set by the European Community (EC), except for three sites namely Amber, Swabi (0.82 mu g/l), Lahore Shakh, Chota Lah ore (0.50 mu g/l) and Madras Kalay, Mardan (0.64 mu g/l). Correlation betwe en water depth and insecticide residues was iii-defined. Loss in recovery d ue to the matrix effect was found to be 10 to 20%.