Flow Injection-Spectrophotometric Determination of Trace Amounts of Bromide by Its Catalytic Effect on the Hydrogen Peroxide Oxidation of Pyrocatechol Violet

Abstract

A flow injection analytical method is proposed for the spectrophotometric determination of trace amounts of bromide based on its catalytic effect on the oxidation of Pyrocatechol Violet by hydrogen peroxide in strongly acidic solution. Bromide in water samples can be determined at a sampling rate of 45h-1 with 500μl sample injections. The detection limit is 10μg l-1 and the calibration graph for bromide is linear over the range of 10-600μg l-1. The relative standard deviations are 2.5% for 20μg l-1 bromide and 1.4% for 105μg l-1 bromide. The procedure is applied successfully to the determination of bromide in natural waters.