Direct measurement of trace rare earth elements (REEs) in high-purity REE oxide using the Agilent 8800 Triple Quadrupole ICP-MS with MS/MS mode

Význam tématu

Rare earth elements play a crucial role in advanced technologies, including permanent magnets, lasers and phosphors. Trace impurities in high-purity REE oxides can compromise functionality of final products. Reliable determination of these contaminants is essential for quality control in materials manufacturing and research.

Cíle a přehled studie / článku

This study evaluates direct measurement of trace REE impurities in single-element REE oxides using an Agilent 8800 Triple Quadrupole ICP-MS with MS/MS mode. The goal is to achieve ppt-level detection limits and to simplify analysis by combining mass-shift and on-mass reaction modes in a single method.

Použitá metodika a instrumentace

The Agilent 8800 ICP-QQQ was operated in tandem MS configuration featuring a Q1 mass filter, ORS3 cell and Q2 filter. Two cell gas modes were applied:

• O2 mass-shift mode to convert analyte ions to MO+, shifting them away from matrix-based interferences
• NH3 on-mass mode to preferentially react and remove polyatomic interferences while measuring analyte ions at their original mass

Standard plasma settings were used with Ni cones, MicroMist nebulizer, Peltier-cooled spray chamber and quartz torch. Cell tuning parameters included octopole bias and RF, KED voltage and optimized gas flow rates.

Hlavní výsledky a diskuse

In a 1 ppm Sm matrix, O2 mass-shift mode reduced SmO+, SmOH+ and SmOH2+ interferences on Dy, Ho, Er, Tm and Yb by nearly two orders of magnitude, yielding detection limits below 0.1 ppt. In a 1 ppm Gd matrix, NH3 on-mass mode effectively eliminated GdO+ overlap on Yb+, achieving background equivalent concentrations below 1 ppt. Some REEs (La, Ce, Nd, Sm, Gd, Tb, Lu) reacted too efficiently with NH3 to allow on-mass measurement and were analyzed in O2 mass-shift mode.

Přínosy a praktické využití metody

This combined-mode approach enables fast, automated ppt-level quantification of all REE impurities in high-purity oxide materials. It streamlines workflow by avoiding time-consuming offline matrix separations. The method is adaptable for QA/QC of semiconductor, magnet and phosphor production and can extend to complex natural samples such as geological digests.

Budoucí trendy a možnosti využití

Developments may include expanding reaction gas chemistries, refining automated multi-tune sequences and integrating direct analysis with online sample introduction systems. Application to a broader range of matrices and real-time monitoring could further enhance control of REE purity in research and industry.

Závěr

The Agilent 8800 ICP-QQQ MS/MS approach using combined O2 mass-shift and NH3 on-mass modes delivers accurate, interference-free trace REE analysis at ppt levels. This versatile method meets stringent purity requirements in high-technology materials and offers potential for diverse analytical applications.

Reference

Sugiyama N, Woods G. Direct measurement of trace rare earth elements in high-purity REE oxide using the Agilent 8800 Triple Quadrupole ICP-MS with MS/MS mode. Application note. Agilent Technologies 2012; Pub no. 5991-0892EN.