An automatic and low-maintenance chelator ion chromatography method for rare earth element determination in...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Traditional rare earth element (REE) detection methods for industrial production are often expensive, require high maintenance, and are unsuitable for continuous monitoring.
• Unconventional feedstocks present challenges for accurate and efficient REE quantification in complex process streams.

Purpose of the Study:

• To develop an automated, low-maintenance, and cost-effective chelation ion chromatography (CIC) method for continuous REE monitoring.
• To optimize the CIC method for enhanced performance and robustness in industrial settings.

Main Methods:

• Development and hardware configuration of an automated CIC system with post-column reagent delivery.
• Optimization of dilution matrices, eluent gradients, and coloring agent composition.
• Calibration for 16 REEs and evaluation of matrix interferences, including high salt concentrations and aluminum ions.

Main Results:

• The optimized CIC method achieved detection limits of 0.089-0.12 mg/L for 16 REEs.
• The method demonstrated robust performance with high recovery rates (95.8%-103%) in the presence of high salt concentrations (up to 10,000 mg/L).
• Aluminum ions were identified as a significant interfering ion, impacting REE recovery at concentrations above 200 mg/L.

Conclusions:

• An automated, low-maintenance, and salt-tolerant CIC technique has been successfully developed for continuous REE monitoring.
• This cost-effective method supports process optimization in industrial settings, particularly for unconventional feedstocks.
• Further investigation into mitigating aluminum interference is recommended for broader applicability.