Highly Sensetive Reaction for the Estimation of Carbaryl Using 4-4ˊ- Diaminodiphenyl Sulfone in Environmental Samples

Abstract

A rapid, sensitive Spectrophotometric method for the determination of ultra trace amount of carbaryl (1- Napthyl-N- Methyl Carbamate) is proposed. The method is based on an alkali hydrolysis of carbaryl in the presence of methanolic KOH, followed by coupling with diazotized 4-41- diaminodiphenyl sulfone in an alkaline medium. The water soluble pink dye obtained shows an absorption maximum at 540 nm. The system obeys Beer’s law over the range of 0.06-2.0μg mL-1. The absorptivity of the coloured product is 7.014 × 104 l mol-1 cm-1 and the developed colour is stable for 48h. The detection limit of Carbaryl is 0.0102 μg mL-1. This method is a very good alternative tool and it can be used successfully for the determination of carbaryl residue in environmental water and grain samples.