HPLC separation post-column reaction, UV-visible and fluorescence detection of trace UO/sub 2//sup 2 +//U/sup 4 +/ species in aqueous solutions
In this study a method for the measurement of uranium in natural waters at sub-ppB concentration levels by the separation and determination of U/sup 4 +/ and UO/sub 2//sup 2 +/ species is proposed. Reversed phase high performance liquid chromatography, followed by a post-column reaction and a sensitive UV-visible detection system was the method of choice to determine qualitatively and quantitatively the two uranium species. Also a cation-exchange and fluorescence detection system was studied for separation and determination of UO/sub 2//sup 2 +/ ions. Uranyl ion was selectively complexed with L-phenylalanine moetie in the sample solution containing U/sup 4 +/ ions. Uranium (IV)/U(VI)-ligand was separated on a C/sub 18/ column with acetate buffer. Hexanesulfonate was found to be the choice for ion-pair reagent. The separation was best done with the acetate buffer at .01 M concentration and pH of 3.5. Absorption of the two species were measured after a post-column reaction with Arsenazo-III. Chromatographic parameters were calculated and a calibration curves were constructed. The detection limit for the procedure was 0.7 ..mu..g/mo and 1.2..mu..g/ml for U(IV) and U(VI) respectively. When U(VI) was separated on the cation-exchange column the limit of detection was calculated to be 1 ..mu..g/ml. The direct fluorometric method for U(VI) measurement results in a detection limit of 2 ppB and upper concentration limit of 2 ppM. The effect of interfering ions in the direct method of determination could be eliminated by dilution of sample solution.
- Research Organization:
- Oklahoma State Univ., Stillwater (USA)
- OSTI ID:
- 6034129
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400702 -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACTINIDE COMPOUNDS
AQUEOUS SOLUTIONS
CATIONS
CHARGED PARTICLES
CHEMICAL ANALYSIS
CHROMATOGRAPHY
DISPERSIONS
IONS
LIQUID COLUMN CHROMATOGRAPHY
MIXTURES
QUANTITATIVE CHEMICAL ANALYSIS
SEPARATION PROCESSES
SOLUTIONS
URANIUM COMPOUNDS
URANYL COMPOUNDS