A simple sensitive spectrophotometric method for determination of dichlorvos in environmental samples

Abstract

A sensitive method has been developed for spectrophotometric determination of an organophosphorous pesticide dichlorvos, also known as 2,2 dichlorovinyl methyl phosphate or dichlorophos. The method is based on hydrolysis of dichlorvos by sodium hydroxide to produce dichloroacetaldehyde, which on coupling with phloroglucinol in alkaline medium, gives orange colour. The orange dye shows absorption maxima at 475 nm and obeys Beer's

law in the range of 10-100μg/25 mL (0.4 to 4 ppm) of solution. The molar absorptivity and Sandell's sensitivity were found to be 4.53×10⁴l mol^-1cm^-1 and 0.0048 μg cm^-2 respectively. The method has been successfully applied for the determination of dichlorvos in water, agricultural soil and vegetables.