Flow-injection extraction-spectrophotometric determination of perchlorate with brilliant green

Abstract Perchlorate (0-2.5 μg ml −1 ) is determined spectrophotometrically at 640 nm after extraction into benzene of its ion-associate with Brilliant Green in a flow-injection manifold with a membrane separator. The injection rate is 20 h −1 . The detection limit is 36 ng ml −1 , based on 250-μl injections. The system is applied to the determination of perchlorate in potassium chlorate after prior selective destruction of chlorate.