Nu Instruments | Nitrogen and Carbon Stable Isotope Analysis with the Horizon IRMS

Stable isotope ratio analysis of nitrogen and carbon using elemental analyser isotope ratio mass spectrometry (EA-IRMS) is widely used across environmental, biological and geochemical applications. This application note evaluates the performance of the Horizon IRMS when interfaced with a EuroVector EURO EA 3000 elemental analyser.

Two experiments were performed to assess instrument performance. The first examined whale baleen keratin samples across a wide range of nitrogen and carbon masses, while the second analysed multiple pre-weighed biological and organic samples from U.C. Berkeley. The results demonstrated consistent isotope ratio measurements across varying sample sizes and compositions.

The study highlights key features of the Horizon IRMS, including programmable CO₂ dilution, automated peak centring, continuous flow operation and programmable reference gas injection. The system achieved excellent precision, linearity and long-term stability, with minimal drift observed throughout the analytical runs.

Key Takeaways:

• Demonstrates accurate δ¹⁵N and δ¹³C measurements across a broad range of sample sizes.
• Automated peak centring and programmable dilution support reliable long-term performance.
• Excellent precision, stability and linearity were achieved during routine EA-IRMS analysis.