Kinetic-spectophotometric determination of hydrazine by the inhibition of the bromate-hydrochloric acid reaction

A simple, sensitive, accurate and selective method for rapid determination of hydrazine is described which is based on its inhibition effect on the reaction between bromate and hydrochloric acid. The decolourisation of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 525 nm. The method allows the determination of hydrazine in the range 3.0 x 10(-7)-3.2x10(-5) M. The relative standard deviation for 10 determinations of 6.25 x 10(-6) M hydrazine is 1.2% and the detection limit of the method is 8.5 x 10(-8) M. The method is applied to the determination of hydrazine present in water. (C) 2000 Elsevier Science B.V. All rights reserved.