A NOVEL SPECTROPHOTOMETRIC DETERMINATION OF CARBARYL PRESENT IN VARIOUS ENVIRONMENTAL SAMPLES

A new and more sensitive method is developed for the determination of carbaryl pesticide, carbaryl from various environmental samples. Carbaryl on its alkaline hydrolysis gives 1-naphthol which is further diazotized with diazonium salts of 4-bromoaniline in an alkaline medium is explained. A yellow dye were obtained by coupling of the pesticide with DBA. The absorbance maxima of yellow coloured dye formed is measured at 517 nm. Beer’s law is obeyed over the concentration range of 0.5 to 8.0 μg mL-1 of carbaryl in a final volume of 25 mL. Molar absorptivity and Sandell’s sensitivity were found to be 6.71×105 L mol-1 cm-1 and 0.0301 μg cm-2 respectively. Some variables were studied in order to optimize the reaction conditions. The experimental results indicate that the procedure can eliminate the fundamental interferences developed by other pesticides and non-target ions, thus the method was more sensitive. This method has been successfully applied for the determination of carbaryl in water, soil, rice, vegetable and various outdoor environmental samples.