Flotation-Dissolution-Spectrophotometric Determination of Phorate in Various Environmental Samples

Abstract

The proposed method is based on flotation–dissolution an easy, impressible, extractive spectrophotometric determination, explained for easy investigation of the organophosphate pesticide phorate (O,O-diethyl S-[ethylthiomethyl] phosphorodithioate) on trace levels. A molybdophospho complex is generated when prorate is treated with ammonium molybdate in acidic medium. As an ion associate complex with methylene blue the complex is present in between of the water and organic layers which is extracted and then dissolved with acetone. The greenish blue complex produced show absorption maxima at 660 nm. Beer’s law range is found to be 0.5 to 16 µg per 10 ml for phorate. The molar absorptivity is 0.989×103 L mol-1 cm-1 and sandell’s sensitivity is 1.00×10-5 µg cm-2. Also calculated the standard deviation and relative standard deviation for the above method were ±0.006 and 1.95% respectively. The method has been applied and checked for the determination of phorate in water, soil and vegetables.