Journal of Analytical & Bioanalytical Techniques
Open Access

Abstract

The analysis of 20 organochlorine pesticides has been carried out in surface water samples collected from Peshawar, KPK, Pakistan, using SPME-GC-ECD method. This method showed good liner response with R 2 values in the range of 0.9933 to 0.9999 for all pesticides. Percent recoveries at 1 μg L -1 for all the pesticides ranged from 89.9 to 106.1%. A total of 59 surface water samples were tasted for 20 organochlorin pesticides residues, of which, 37 samples were found contaminated with γ-BHC, 12 samples with β-BHC, 25 samples with heptachlor and 25 samples with aldrin with a maximum concentration of 0.092, 0.053, 0.089 and 0.036 μg L -1 , respectively. However other pesticides were found in lesser no. of water samples. The gamma irradiation decomposition of monocrotophos aqueous solution at various concentrations (60-150 mg L -1 ) was carried out and their removal efficiency was investigated. Gamma irradiation showed 100% degradation for a 60 mg L -1 solution at an absorbed dose of 1200 Gy. The dose constants investigated in this study ranged from 1.4 X 10 -3 to 3.0 X 10 -3 Gy -1 . The effect of saturated solutions of N 2 and N 2 O, and radical scavengers such as tert-butanol, iso-propanol, H 2 O 2 , NO 3 - and NO 2 - on the degradation of monocrotophos were also studied. The results showed that degradation of monocrotophos mainly proceeded through oxidative ?OH radical. The organic by-products were determined by UPLC/MS/MS and inorganic by-products NO 3 - , NH 4 + and PO 4 3- were quantitatively determined by ion chromatography. A detail mechanism pathway of monocrotophos degradation by irradition has been developed.

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