New Analytical Method Tracks Rare Earths Through the Magnet Supply Chain

• Ghent University researchers developed a refined ICP-MS method combining chemical separation techniques to accurately measure rare earth element composition in Nd-Fe-B magnets, overcoming interference from high iron content that plagued conventional analysis.
• Analysis across the production chain—from mining concentrates to finished magnets—revealed stable REE distribution patterns, with neodymium and praseodymium representing ~90% of rare-earth content in magnets versus lanthanum-cerium dominance in concentrates.
• The improved analytical approach could strengthen supply-chain certification and transparency for critical materials used in electric vehicles, wind turbines, and defense technologies, though isotopic analysis will be needed for robust source attribution.

---

A new study led by Laura Suárez-Criado (opens in a new tab) and Prof. Frank Vanhaecke (opens in a new tab) of Ghent University’s Atomic & Mass Spectrometry (A&MS) research unit (opens in a new tab), in collaboration with scientists from CEA-LITEN (opens in a new tab) (France), BRGM (opens in a new tab) (France), and other partners in the EU-funded MaDiTraCe (opens in a new tab) project, presents a refined analytical method for measuring rare earth elements (REEs) throughout the permanent-magnet production chain—from mining concentrates to finished Nd-Fe-B magnets. Published in the Journal of Analytical Atomic Spectrometry (opens in a new tab), the research demonstrates that combining chemical separation techniques with ICP-MS (Inductively Coupled Plasma Mass Spectrometry) allows accurate measurement of rare earth compositions even in iron-rich magnet materials where conventional analysis is prone to severe signal interference. The work aims to strengthen traceability and transparency in rare-earth supply chains, an increasingly urgent issue as these materials underpin electric vehicles, wind turbines, robotics, and defense technologies.

Ghent University’s Atomic & Mass Spectrometry (A&MS) research unit

Study Methods: Solving a Difficult Measurement Problem

Nd-Fe-B magnets contain large amounts of iron—typically more than 65% of the total mass—along with high concentrations of neodymium and praseodymium. In ICP-MS analysis, lighter rare earth elements can generate oxide and hydroxide ions that overlap with signals from heavier elements such as dysprosium, terbium, or erbium, producing inaccurate measurements.

To address this challenge, the research team developed a two-stage separation workflow. First, iron was removed using an AG® MP-1M anion-exchange resin. Next, rare earth elements were separated from one another using LN-resin ion-exchange chromatography, after which concentrations were measured by ICP-MS. The approach was tested on samples spanning the entire value chain: mining concentrates, Nd-Pr alloy feedstock, strip-cast ribbons, magnet powders, and finished magnets.

Key Findings: Chemical Signatures Across the Value Chain

The analysis revealed several consistent patterns:

• Concentrates from Bayan Obo (China) and Mountain Pass (United States) are heavily enriched in light rare earth elements, especially lanthanum and cerium.
• In contrast, Nd-Fe-B magnets are dominated by neodymium and praseodymium, which together often represent about 90% of total rare-earth content.
• Samples analyzed at different stages of a magnet production chain showed remarkably stable REE distribution patterns, indicating little chemical fractionation during manufacturing.
• Minor variations in trace elements such as Ce, Sm, Gd, and Dy were observed and likely reflect equipment carry-over or processing contamination rather than intentional changes in alloy chemistry.

These results indicate that REE patterns can provide useful chemical fingerprints for materials within magnet supply chains. However, the authors emphasize that such patterns alone cannot reliably determine the geological origin of the raw material, as metallurgical processing alters elemental ratios.

Implications for Rare Earth Supply Chains

Improved analytical tools for REE measurement could play a key role in supply-chain certification and transparency, particularly as governments and manufacturers seek to diversify rare-earth sourcing. Accurate compositional analysis may help identify recycled material streams, verify sourcing claims, and strengthen oversight of critical mineral supply chains.

Study Limitations

The work focuses primarily on analytical methodology rather than industrial-scale implementation. Some measurements were influenced by procedural blanks and trace contamination, particularly for elements present at very low concentrations. The authors note that isotopic analysis—especially of neodymium—will likely be required for robust source attribution.

What Comes Next

Future research may combine elemental analysis with isotopic fingerprinting and digital traceability systems, potentially enabling more reliable certification of rare-earth materials used in advanced technologies.

Citation: Suárez-Criado, L.; Rado, C.; Losno, D.; Vanhaecke, F. Determination of REEs in permanent magnets and their production chain using ICP-MS. Journal of Analytical Atomic Spectrometry, 2026. DOI: 10.1039/D5JA00513B.