The Advantages MICAP-MC-MS Offers in Isotopic Analysis

At the Winter Conference on Plasma Spectrochemistry in Tucson, Arizona, Anika Retzmann, a postdoctoral researcher in the Atom Mass Lab at the University of Calgary, delivered a presentation titled “Introducing MC-MICAP-MS: Metal Isotope Abundance Ratio Measurements Using a N₂-based Plasma Ion Source” (1).

Spectroscopy sat down with Retzmann at the Winter Conference on Plasma Spectrochemistry to talk about her research. In Part I, Retzmann discussed how analyzing elemental and stable metal isotopic compositions of biological systems help answer fundamentally different research questions across fields such as biomedicine and environmental science (2). In Part II, she explains how developing fully automated analyte purification procedures helps improve data quality and reproducibility compared to traditional approaches (3). In Part III, she dives more deeply into the utility of multi-collector microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MC-MICAP-MS) for isotopic analysis.

Spectroscopy: Stable metal isotopes are increasingly used to study the roles of essential elements in biology. What unique insights can isotopic signatures provide that cannot be obtained from elemental concentration measurements alone?

Anika Retzmann: Let me give you an example on that one, coming back to the studies where we were looking at zinc isotopes in mice. For the zinc isotopes in mice, we looked at the different organs, and we had two groups of mice. One mice group had gut microbiota, the other one did not have gut microbiota. We compared how these two groups of mice were looking in terms of zinc content and zinc isotopes. For the zinc content, we did not see any difference that was significant between the groups. So that would indicate that there might not be a dysregulation, or there might not be a change to the zinc homeostasis that is induced by the absence or the presence of the gut microbiota. But when we looked at the zinc isotopes, we saw that the gut microbiota actually plays a crucial role in the homeostasis of zinc, and then its absence actually changes the balance here, so that's something that we wouldn't have seen if we would only have looked at the concentrations here.

This video clip is the third part of our conversation with Retzmann. 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 2026-01-20).
2. Wetzel, W. Analyzing Elemental and Stable Metal Isotopic Compositions of Biological Systems. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/analyzing-elemental-and-stable-metal-isotopic-compositions-of-biological-systems (accessed 2026-01-20).
3. Wetzel, W. The Benefits of Using Automated Analyte Purification Procedures. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/the-benefits-of-using-automated-analyte-purification-procedures (accessed 2026-01-20).