Nu Instruments | High Precision Static Calcium Isotope Measurements with Nu TIMS

Calcium isotopes provide valuable information about the formation and evolution of planetary materials, including meteorites and rocks from Earth, the Moon and Mars. High-precision isotope ratio measurements are therefore essential for understanding early solar system processes and planetary differentiation.

This application note explores the performance of the Nu TIMS instrument for static calcium isotope measurements. The system's Zoom Optics technology enables each measurement line to be independently optimised and electronically switched within milliseconds, improving alignment, accuracy and long-term measurement stability without requiring movable detectors.

Using a 1 μg Calcium NBS 915b standard, the study achieved excellent reproducibility across multiple calcium isotope ratios. Average results included 23 ppm (1 RSD) for ⁴⁰Ca/⁴⁴Ca, 65 ppm for ⁴³Ca/⁴⁴Ca and 26 ppm for ⁴⁸Ca/⁴⁴Ca. The data demonstrates that precisions below 25 ppm (1 RSD) for ⁴⁰Ca/⁴⁴Ca are achievable using the described measurement approach.

Key Takeaways:

• Achieves 23 ppm (1 RSD) reproducibility for ⁴⁰Ca/⁴⁴Ca measurements using a 1 μg calcium standard.

• Zoom Optics technology enables rapid electronic switching between optimised measurement lines.
• Demonstrates high-precision calcium isotope analysis for geochemistry and planetary science applications.