Determination of Uranium by Spectrophotometric Method with Arsenazo III

Abstract

Uranium is separated and preconcentrated from interfering elements
by liquid extraction with 20% tributylphosphate (TBP) in benzene solution,
prior to spectrophotometric determination with Arsenazo III in
HCl medium (pH = 2.5), stabilized by buffer solution. Sodium fluoride
and EDTA are used to complex calcium, rare earth elements (RE) and
iron because they interfere in urani urn determination. The method is
applicable in sediments and soil samples in the range of 0.25-10.0  μg
of U/L. It should be used in water samples, too, in the range up to 0.25
μg of U/L for 20 to 50 mL of water sample.