Determination of bromide in complex matrices by pre-column derivatization linked to solid-phase extraction and high-performance liquid chromatography

Bromide has been determined (i) in the presence of a large excess of chloride and other ions to evaluate its level in sea water, concentrated hydrochloric acid and salts, (ii) after selective mineralization of aliphatic bromo-compounds to measure total bromide residues of fumigants such as 1,2-dibromoethane in water and (iii) to assess bromate levels in water after removal of any free bromide, and reduction of bromate to bromide. The method involves a pre-column derivatization of bromide to 4-bromoacetanilide by reaction with 2-iodosobenzoic acid and acetanilide, sample clean-up by solid-phase extraction using C-18 cartridges and high-performance liquid chromatography. The method is simple and precise and has a limit of detection of 1 mu g/l bromide.