Supramolecular based-ligandless ultrasonic assisted-dispersion solidification liquid–liquid microextraction of uranyl ion prior to spectrophotometric determination with dibenzoylmethane

A simple, efficient, rapid and environmentally friendly method has been developed for preconcentration and determination of ultratrace amounts of uranyl ion in water sample by a supramolecular based-ligandless ultrasonic assisted-dispersion solidification liquid–liquid microextraction procedure before spectrophotometric detection. The methodology is based on the dispersion-solidification liquid–liquid microextraction of uranyl ion with decanoic acid/THF supramolecular solvent in the absence of chelating agent. Several factors affecting the microextraction efficiency, such as pH, type and volume of supramolecular solvent, sonication time, and ionic strength were investigated and optimized. Under the optimized conditions, the enhancement factor and preconcentration factor were obtained as 54.43 and 33.33 respectively. The calibration curve was linear in the range of 4.00 to 311.85 ng mL−1 of uranyl ion with R2 = 0.9967 and the detection limit based on three times the standard deviation of the blank (3Sb) was 2.00 ng mL−1 in the original solution. The relative standard deviation for seven replicate determination of 125.00 ng mL−1 uranyl ion was ±2.87%. The developed method was successfully applied to the extraction and determination of uranyl ion in natural water samples.