Automated determination of bromide in waters by ion chromatography with an amperometric detector

An automated ion chromatograph, including a program controller, an automatic sampler, an integrator, and an amperometric detector, was used to develop a procedure for the determination of bromide in rain water and many ground waters. Approximately 10 min is required to obtain a chromatogram. The detection limit for bromide is 0.01 mg l⁻¹ and the relative standard deivation is <5% for bromide concentrations between 0.05 and 0.5 mg l⁻¹. Chloride interferes if the chloride-to-bromide ratio is greater than 1 000:1 for a range of 0.01–0.1 mg l⁻¹ bromide; similarly, chloride interferes in the 0.1–1.0 mg l⁻¹ range if the ratio is greater than 5 000:1. In the latter case, a maximum of 2 000 mg l⁻¹ of chloride can be tolerated. Recoveries of known concentrations of bromide added to several samples, ranged from 97 to 110%.