Fluorimetric determination of uranium in sea water by amidoxime-resin preconcentration

Amidoxime resin (AOR) was applied to the fluorimetric determination of uranium in sea water in order to simplify the preconcentration operation. Uranium was completely recovered by passage of 500 ml of sea water through a column packed with 5 ml of AOR at a flow rate below 12 h-1 SV. Elution of uranium with ammonium carbonate as an eluant was incomplete. Acidic eluants eluted uranium almost quantitatively, although Fe, which caused extinction of fluorescence, was eluted from the resin. Therefore, removal of Fe from the eluate of H2SO4 by anion-exchange method was introduced. Analytical results by the AOR preconcentration method agreed with those obtained by the AlPO4 coprecipitation method, and a relative standard deviation of 2 % was achieved. (author)