Preconcentration of rare earth elements on activated carbon and its application to groundwater and sea-water analysis

Abstract

Systematic investigations were carried out into the sorption of REEs, Y and Sc on activated carbon. Experimental parameters, such as the effect of pH, amount of carbon, contact time, sample solution volume and various mineral acids for desorption, were optimized for quantitative recoveries. The procedure was applied to the determination of REEs in Indian sea-water and groundwater by ICP-MS. The practical limit of determination with an enrichment factor of 400 is 0.3 pg ml^–1(based on the preconcentration of 2000 ml of sample to 5 ml). The precision of the method is 10% at the 0.3 pg ml^–1 level. The preconcentration method is simple, expeditious and field-oriented with a simple single-stage separation of the REEs from Ba and the salt content.