Enhancing Isotopic Precision

Continuing our coverage of the Winter Conference on Plasma Spectrochemistry, Spectroscopy sat down with Ken Marcus, Adger Bowen Professor of Chemistry at Clemson University, to talk about his work in isotope ratio analysis (1–4).

The first two parts of our conversation with Marcus focused on specific topics in isotope analysis, such as the implications of monitoring oxide species rather than atomic ions (4). In this final segment, he addresses two major questions, one about how external acquisition system enhance isotopic precision and the other about the latest spectroscopic trends that experts and industry professionals should take note of.

Spectroscopy: In what ways do external acquisition systems like the FTMS Booster enhance isotopic precision and signal-to-noise performance, and how might these improvements influence future analytical workflows in nuclear forensics or REE isotope studies?

Ken Marcus: The Orbitrap (orbital ion trap) and how that signal is processed is a Fourier transform process. Basically, what the key parameters are is the longer you can observe whatever it is. In our case, the more the ions spin around in the Orbitrap cell, the higher the signal to noise (S/N) ratio becomes, and the better the resolution becomes. And furthermore, the mass accuracy becomes so long that the transients are very good. And then, you have the capability of taking multiple transients from the same sample. For a single particle, you only get one shot at it. But if we introduce a 10-microliter injection, then we might get 10s and hundreds of transients and those come together and improve the signal-to-noise. If I can look at a whole milliliter, then I'm taking 1000s of transients and getting improved signal-to-noise even further.

This video clip is the final part of our conversation with Marcus. To stay up to date on our coverage of the Winter Conference, click here.

References

1. IASA, Winter Conference on Plasma Spectrochemistry. IASA. Available at: https://iasa.world/winter-plasma-conference (accessed 2026-01-19).
2. Clemson University, R. Kenneth Marcus. Clemson.edu. Available at: https://www.clemson.edu/science/academics/departments/chemistry/about/profiles/marcusr (accessed 2026-01-19).
3. Wetzel, W. Improving High-Resolution Mass Spectrometry Platforms. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/improving-high-resolution-mass-spectrometry-platforms (accessed 2026-01-22).
4. Wetzel, W. What Really Improves Nd Isotope Ratios? Spectroscopy. Available at: https://www.spectroscopyonline.com/view/what-really-improves-nd-isotope-ratios- (accessed 2026-01-23).