ONLINE SOLID-PHASE EXTRACTION AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY FOR THE DETERMINATION OF BROMIDE

In the chromatographic determination of bromide at mu g/l level, probl ems are faced due to interference ofchloride and high acidity usually present in real samples. These problems are obviated In the present st udy by a combination of solid-phase extraction and HPLC. The precolumn reaction of bromide with 2-iodosobenzoic acid and acetanilide to form 4-bromoacetanilide has been coupled to on-line pre-concentration and clean-up of derivative by solid-phase extraction using C-18 sorbent. P re-concentration of up to 50 ml of sample (without any breakthrough of 4-bromoacetanilide from extraction cartridge) and transfer of total e xtract, rather than an aliquot of it, on to the analytical column allo ws achievement of a high sensitivity. High concentrations of ionic imp urities including chloride as found in salts, concentrated hydrochlori c acid and sea water, which interfere in conventional ion chromatograp hy for bromide, can be tolerated. The proposed method (limit of detect ion of 0.2 mu g/l bromide) has been applied for analysis of real sampl es such as salts, cone. HCl, and sea water.