A flow injection system incorporating a microcolumn of activated alumina was combined with inductively coupled plasma mass spectrometry for on-line trace enrichment and determination of uranium in surface waters and sea water. Deposition of uranium was effected with the use of a basic alumina microcolumn, and injection of nitric acid (250 μL, 2M) served to elute retained species to the ICP. A sample volume of 14 mL resulted in a preconcentration factor of 40, and precision at the 50-ng 1−1 level was 4.5% (RSD). The procedure was applied to mineral waters, river water, and sea water, and accuracy was assessed through either analysis of certified reference waters or recovery experiments.
