Degradation of Some Organophosphorous Pesticides under Different Field Conditions

Abstract

HPLC procedure for the determination of methylparathion and malathion in radish, carrot and the soil has been developed to measure the decay pattern of the pesticides in three different seasons winter, summer and post-monsoon. The pesticide was extracted and chromatographed on a μ bondapak RP-C₁₈ column using a mixture of acetonitrile and water and detected using an ultraviolet detector. The decay in winter and post-monsoon is linear while in summer two distinct profiles are observed. The degadation is faster in summer than the other two seasons. There are no significant differences in the degradation pattern of the pesticides on the two plants. The rate is faster in soil than on the plants. These results present a data base depicting the effect of temperature and humidity on the degeneration of pesticides on plants and in soil.

Keywords:

• Pesticides
• decay
• seasonal variation
• root vegetables
• soil