On-line method for inductively coupled plasma mass spectrometric determination of rare earth elements in highly saline brines
Abstract
A rapid and reliable on-line preconcentration method for the determination of REE in sea-water and highly saline brines by ICP-MS was developed. The method is based on REE separation from the saline water by adsorption on a micro-column of silica-immobilized 8-hydroxyquinoline. After 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 waters range from 0.06 ng lā1 for Tb and Ho to 0.6 ng lā1 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 literature.