ONLINE METHOD FOR INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRIC DETERMINATION OF RARE-EARTH ELEMENTS IN HIGHLY SALINE BRINES

A rapid and reliable on-line preconcentration method for the determina tion of REE in sea-water and highly saline brines by ICP-MS was develo ped. The method is based on REE separation from the saline water by ad sorption on a micro-column of silica-immobilized 8-hydroxyquinoline. A fter adsorption on the micro-column at pH 9, the REE are eluted with a small volume of mixed acids and introduced into the ICP-MS instrument . The system operates at low pressure. Total time of preconcentration and analysis is less than 10 min. Detection limits in highly saline wa ters range from 0.06 ng l(-1) for Tb and Ho to 0.6 ng l(-1) for Ce and Nd. Since there is no REE sea-water reference, the analytical results obtained by this method were compared with those quoted in the litera ture.