Determination of uranium in environmental matrices by chelation ion chromatography using a high performance substrate dynamically modified with 2,6-pyridinedicarboxylic acid

Chelation ion chromatography, involving a high efficiency neutral polystyre ne-divinylbenzene resin dynamically coated with 2,6-pyridinedicarboxylic ac id, has been developed as a novel technique for the quantitative determinat ion of uranium in complex matrices. An isocratic separation method, using a n eluent consisting of 1M KNO3, 0.5M HNO3 and 0.1 mM 2,6-pyridinedicarboxyl ic acid, allowed the uranyl ion to elute away from matrix interferences in under ten minutes. Detection was achieved using an Arsenate III post column reaction system. Good recoveries were obtained from spiked mineral water a nd sea water and the standard addition curves produced good linearity (r(2) > 0.997) with a detection limit, calculated as twice baseline noise, of 20 mu g L-1. The procedure was applied to the determination of trace uranium in standard reference water and sediment samples. The results obtained comp ared well with the certified values for uranium.