Determination of some carbamate insecticides with N-bromosuccinimide reagent

A quick and convenient method has been developed for the milligram determination of some carbamate insecticides. The sample is allowed to react with a calculated excess of (0.02N) N-Bromosuccinimide (NBS) reagent in the presence of glacial acetic acid and HCI for 5-10 min. at room temperature (25°C -30°C). After the reaction is over, 5 ml of KI solution (10%) is added and the unreacted reagent is back titrated with 0.02N solution of sodium thiosulphate to starch endpoint. The method is applied for the determination of technical samples and formulations of Carbaryl, Propoxur, Methiocarb, Bendiocarb and Aldicarb. The results are with in error of ′ 1.0%.