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

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 (Delta A) 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.