A novel method for extractive spectrophotometric determination of uranium by Azur II dye in some geological samples

ABSTRACT

A novel and really simple method for extractive photometric determination of uranium is achievable by Azur II dye with accurate and sensitive results. This has been possible through a basic dye (Azur II) that reacts firstly with a suitable ligand (benzoate) to form a triple complex. The latter is then extracted in a suitable organic solvent (Trioctylamine). Optimisation of the formed U-benzoate-Azur II complex was performed by studying several parameters such as suitable pH, dye concentration, duration time of the formed complex, solvent concentration, shaking time and U concentration (calibration curve). This reagent is extremely sensitive to uranium, with a molar absorption potential of 0.654 × 10⁴ L. M⁻¹ cm⁻¹ at pH 4 at 688 nm. Absorbance measurements showed as time function that the coloured complex is stable up to 20 min. This system allows uranium content to be calculated with a detection limit (LOD) of 0.15 µg L⁻¹, and precision expressed as relative standard deviation (RSD) of 0.368%. The tolerance limits had been calculated for several metal ions. Accuracy was confirmed by U (VI) determination in the standard reference materials. This new spectrophotometric method was applied for the determination of U(VI) in some cataclastic rock samples with accurate results.

KEYWORDS:

• Spectrophotometric
• uranium
• Azur II
• extractive spectrophotometric
• trioctylamine

Acknowledgments

The author gratefully acknowledges to my Research team of Nuclear Materials Authority (Dr Nagwa I. Falila, Dr Doaa A. Ismaiel and Dr Shaimaa Abdulmoteleb) for their support and help.

Disclosure statement

The authors declare that they have no conflict of interests.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Additional information

Funding

This research did not receive any specific funding.