A Robust Cost-Effective Spectrophotometric Method for Nb Determination in Refractory Nb-doped Gadolinium Zirconate:...

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Determining niobium (Nb) in highly refractory materials like Nb-doped gadolinium zirconate and niobium pentoxide presents significant analytical challenges.
• Traditional digestion methods can be complex and require harsh conditions, limiting their applicability.

Purpose of the Study:

• To develop a simple, robust, and cost-effective analytical methodology for niobium determination in challenging refractory matrices.
• To establish reliable dissolution procedures and optimize a spectrophotometric method for accurate Nb quantification.

Main Methods:

• Developed two independent digestion procedures: fluoride-free reflux and microwave-assisted digestion with minimal hydrofluoric acid.
• Optimized a one-step spectrophotometric method for niobium determination via peroxoniobium complex formation in sulfuric acid medium.

Main Results:

• Achieved a wide linear dynamic range (2-225 ppm Nb) with a high regression coefficient (0.99945) and a low detection limit (0.4 ppm).
• Demonstrated high precision (method RSD 2.13%) and excellent recovery (>98%) for spiked samples.
• Validated the method using X-ray fluorescence techniques, showing good agreement.

Conclusions:

• The developed dual digestion and spectrophotometric method is reliable, flexible, and cost-effective for analyzing niobium in highly refractory materials.
• The method offers a straightforward approach with reduced procedural steps and chemical inventory.
• Independent validation confirms the accuracy and robustness of the proposed analytical technique.