Abstract
A rapid preconcentration method for uranium(VI) in seawater based on the extraction-back extraction with capriquat (trioctylmethylammonium chloride) system is described. Uranium(VI) is extracted as the thiocyanate from 400 cm3 of a seawater sample into 30 cm3 of 2 × 10-2 mol dm-3 capriquat in benzene and back-extracted into 3 cm3 of 5.5 mol dm-3 perchloric acid containing Arsenazo III. By using this method, uranium(VI) in seawater with levels below ppb range could be determined by spectrophotometry. Other cations in seawater are found not to cause interferences. A relative standard deviation of 2.4% can be achieved.
