SIMPLE AND RAPID FLOW-INJECTION SPECTROPHOTOMETRIC DETERMINATION OF CARBARYL AFTER LIQUID-LIQUID-EXTRACTION

A simple procedure was developed for the spectrophotometric determinat ion of carbaryl and its hydrolysis product 1-naphthol in water. These compounds are extracted into xylene and back-extracted, as the 1-napht holate, with 0.2 M NaOH. A 600-mul volume of the alkaline extract is i njected into a flow analysis manifold which provides the reaction betw een naphtholate and 50 mug ml-1 p-aminophenol solution in the presence of 0.004 M KIO4 and spectrophotometric measurement is carried out at 596 nm. The method provides a limit of detection of 26.5 ng ml-1 carba ryl and a sample frequency of 110 injections per hour. Recoveries in d ifferent types of matrices vary from 95 to 102%.