DETERMINATION OF BROMIDE IONS IN SEAWATER BY CAPILLARY-ZONE-ELECTROPHORESIS USING DILUTED ARTIFICIAL SEAWATER AS THE BUFFER SOLUTION

A novel capillary zone electrophoresis method was developed for the de termination of bromide ion in seawater. A tenfold-diluted artificial s eawater was adopted as the buffer solution, to prevent interference fr om high concentrations of chloride ion in seawater. No electroosmotic flow reverser was used to shorten the analysis time. It was found that the peak area and migration time for bromide ion were almost constant , despite differences in the salinity of sample solutions; the peak he ight decreased linearly with an increase in the salinity. The limit of detection for bromide ion was 0.46 mg/l (S/N=3). The values of the re lative standard deviation for peal; area and migration time for bromid e ion were 1.4 and 1.5%, respectively. The proposed method was applied to the determination of bromide ion in seawater samples taken from th e surface and the sea-bed. The analytical results obtained by the work ing curve method agreed with those obtained by the standard addition m ethod. The method may be applicable to the determination of other ions , such as nitrite and nitrate ions, in seawater (C) 1998 Elsevier Scie nce B.V.