Nu Instruments | High Precision Molybdenum Isotope Analysis Using Nu TIMS

Molybdenum isotope anomalies provide important insights into planetary formation, extraterrestrial materials and Earth's accretion history. These subtle isotope variations require highly precise analytical techniques, making thermal ionisation mass spectrometry (TIMS) a preferred approach for advanced isotope studies.

This application note outlines the use of the Nu TIMS system for measuring molybdenum isotopes in negative ion mode using MoO₃⁻ species. The instrument's zoom optics and 16-Faraday collector configuration enable precise peak alignment and simultaneous collection of isotope signals, helping to minimise analytical uncertainty while maintaining excellent measurement accuracy.

Results demonstrate outstanding reproducibility from just 1 µg of molybdenum. Online oxide corrections, flexible multi-static and multi-dynamic measurement modes, and long-term instrument stability contribute to highly precise isotope ratio determinations. The study also highlights the benefits of measuring all isotopes during each acquisition cycle, reducing errors associated with low-abundance signals and improving confidence in isotope data.

Key Takeaways:

• Achieves excellent reproducibility for multiple Mo isotope ratios with precision down to low ppm levels.
• Uses zoom optics and multi-collector detection to maximise peak alignment and measurement accuracy.
• Demonstrates stable, high-precision molybdenum isotope measurements over extended analytical periods.