A new approach for efficient preconcentration of uranyl ions using binary catanionic surfactant system

To facilitate uranium quantification in water samples at trace levels using the common affordable and economic analytical techniques, a preconcentration step is often applied. In this work, a novel, sensitive, reproducible, and quick cloud point extraction procedure was developed to preconcentrate and determine uranyl ions in aqueous solutions using a mixed cationic-anionic surfactant medium. The procedure involved the complexation of uranyl ions with 2-thenoyltrifluoroacetone in acidic media and its extraction into the micellar phase. Electrolyte-induced phase separation was achieved at ambient temperature using potassium iodide, and following centrifugation, the surfactant-rich phase was diluted and uranium content was determined spectrophotometrically. Various factors influencing the preconcentration procedure efficiency, viz. pH value, surfactant content, salt type and amount, ligand amount, and equilibration time were investigated in detail. The effect of several common interfering ions was examined to assess the procedure selectivity. The developed procedure offered a substantially low detection threshold of 0.98 mu g L-1 with an observed linear range from 10 to 350 mu g L-1. The developed procedure was successfully applied to the preconcentration and determination of trace quantities of uranyl ions in spiked water samples at different concentrations, and the % recovery results were found to be between 95.50 and 98.10%.