Retention studies on uranium, thorium and lanthanides with amide modified reverse phase support and its applications

Area of Science:

• Analytical Chemistry
• Nuclear Chemistry
• Separation Science

Background:

• Uranium and thorium retention on modified reverse-phase supports were studied.
• Amide and succinamic acid derivatives (OPAEHA, OPAIBA, BEHSA) were used as stationary phase modifiers.
• Alpha-hydroxy isobutyric acid (alpha-HIBA) served as the complexing agent for elution.

Purpose of the Study:

• To develop a novel high-performance liquid chromatography (HPLC) method for separating lanthanides from uranium.
• To enable simultaneous isolation and quantitative determination of lanthanides within a uranium matrix.
• To improve analytical efficiency for samples from pyrochemical reprocessing of molten salts.

Main Methods:

• Investigated retention behavior of uranium and thorium on modified reverse-phase supports.
• Studied elution profiles based on modifier concentration, mobile phase composition, and pH.
• Developed and applied a BEHSA-modified support HPLC technique for lanthanide and uranium separation.

Main Results:

• A novel HPLC technique using BEHSA-modified support was successfully developed.
• Lanthanides were isolated and quantitatively determined as a group within a uranium matrix.
• Separation and determination of lanthanides in uranium matrix (1:20,000) were achieved within 7 minutes.
• Simultaneous separation and assay of total lanthanides and uranium were demonstrated.

Conclusions:

• The developed HPLC technique offers a significant advantage by enabling simultaneous separation and assay of lanthanides and uranium.
• This method eliminates the need for prior separation of the uranium matrix, unlike other analytical techniques.
• The technique is efficient for analyzing samples from pyrochemical reprocessing, providing rapid and accurate results.