Spectrophotometric determination of carbaryl pesticide and its hydrolysis product in soil and strawberry samples

A spectrophotometric method for the determination of carbaryl in soil and strawberry fruit samples is described. The method is based on the coupling of 1-naphthol obtained from hydrolysing carbaryl with diazotised sulphanilic acid in an alkaline medium to form p-(4-hydroxyl-1-naphtylaza)benzenesulphonic acid which has a maximum absorbance at 475 nm. Beerʹs law is obeyed in the range of 0.01–0.1 ppm of carbaryl. The proposed method is sensitive and rapid. The average carbaryl content of strawberry fruits was 6.03 ppm and the average 1-naphthol content of soil samples was 16.29. The samples were obtained from their sources during 1 day after approx. 24 h of rain.