Kinetic-spectrophotometric determination of trace amounts of bromide based on its catalytic effect on methyl red-bromate reaction

Chemistry Department, College of Science, Shahid Chamran University. Ahvaz, Iran

E-mail : fathiemadabadi@yahoo. com

Manuscript received 7 August 2006, accepted 21 August 2006

A simple, sensitive and rapid method has been developed for kinetic spectrophotometric determination of
trace amounts of bromide. The method is based on the catalytic effect of bromide on the oxidation reaction of methyl red by potassium bromate in the presence of hydrochloric acid. The reaction is followed spectrophotometrically by measuring the change in absorbance (ΔA) at 517 nm using a fixed time method (6 min). The method allows the determination of bromide in the range of 50-1200 ng ml^-1. The proposed method was successfully applied to the determination of bromide in water samples.