Gas chromatographic analysis of pesticide residues in soil of Bahawalpur district, Punjab, Pakistan.

Residues of organophosphate (OP) and organochlorine (OC) pesticides were monitored in soil samples collected from cotton growing areas in Bahawalpur district, Punjab, Pakistan. All the 12 soil samples were found contaminated with dichlorvos, dimethoate, methyl parathion, fenitrothion, endosulfan, mevinphos, chlorpyriphos and profenofos. The most widely detected pesticide was mevinphos and was found in eleven samples with mean concentration of 0.199 mg Kg -1 . Endosulfan was the second most often detected pesticide investigated in ten samples with the mean concentration of 0.262 mg Kg -1 . fenitrothion was the third most detected pesticide in seven samples with mean concentration of 0.3 mg Kg -1 . Profenofos was not detected in any soil sample. The mean value of ∑pesticides was found to be 1.175 ± 0.014 mg Kg -1 at 95% confidence level in soil samples collected with highest value of 3.161 mg Kg -1 in sample MS-3 followed by 2.527 mg Kg -1 in MS-2, while, other samples (83%) were found contaminated usually at concentration less than 2 mg Kg -1