Using the nanoMRR in Teaching and Research: A Q&A with Dr. Twagirayezu

Using MRR and the nanoMRR in Your Lab: A Q&A with Dr. Sylvestre Twagirayezu 

To help chemistry professors explore the potential benefits of molecular rotational resonance (MRR) spectroscopy and BrightSpec’s MRR instrument, we interviewed Dr. Sylvestre Twagirayezu, Associate professor of Chemistry at Lamar University. Here’s what he had to say about his experience using MRR technology, the impact of the MRR on his teaching and research, and its value as a tool for advancing student learning.

 Q: Can you tell us about your background and your research focus?  

 Dr. Twagirayezu: I'm a physical chemist with a background in molecular spectroscopy.  My research group at Lamar University focuses on the use of high-resolution spectroscopic tools to study energy patterns in chemical mixtures with specific goals of contributing to the advancement of molecular spectroscopy and the development of new tools for environmental applications and petroleum processing. Currently, we are leveraging molecular rotational resonance spectroscopy to help achieve those research goals.

 Q: How do you incorporate the nanoMRR into your teaching?  

Dr. Twagirayezu:  By integrating MRR in my environmental analysis and physical chemistry courses, I am able to articulate difficult concepts to students and show practical applications of molecular spectroscopy in the real world.  Additionally, MRR in my lab is routinely used for student learning engagement where a group of students are invited to see my research lab and learn what rotational spectroscopy is and does.

 Q: How do students respond to using the nanoMRR?  

 Dr. Twagirayezu: The operation of the nanoMRR technique itself is straightforward due to its simple and compact design.  The operation process for nanoMRR begins by explaining how it is related to a microwave at home.  In a typical microwave at home, we select food and place it in a microwave oven which warms it up by exciting water hidden in the food. nanoMRR can also be imagined as a “scannable microwave machine” where microwave radiations are used to excite polar analytes in chemical mixtures.  As long as the selected chemical mixture contains small polar molecules with sufficient vapor, nanoMRR can be employed to analyze them. This analogy typically helps students whose background is not rotational spectroscopy. 

 Q: What makes the nanoMRR valuable for both teaching and research?  

 Dr. Twagirayezu : As a teaching tool, nanoMRR has value in terms of complementing the existing laboratory facilities and bringing new analytical tools to train the next generation of chemists to benefit the STEM field. As a research tool, a nanoMRR has specific advantages over other conventional instruments including multi-analysis, chemical specificity, information richness, fast measurements, and column/calibration-free capabilities. 

The nanoMRR’s multi-analysis capabilities are another advantage. For example, with more traditional techniques like gas chromatography, you can analyze multiple analytes, but you have to carefully control for interference, which often requires sample pretreatment. With the nanoMRR, I can just put a sample in the cell, and if there are analytes in the region covered by the nanoMRR, we can detect them without pretreatment.  

 Q: How has the nanoMRR contributed to your research funding?  

 Dr. Twagirayezu:  The availability of nanoMRR has allowed us to secure different research grants. Some examples include the Texas Air Research Center for evaluating nanoMRR, as a new technique for fast detection of sulfur dioxide from point sources, the American Chemical Society Petroleum Fund for the studies of small polar impurities in petroleum mixtures, and NSF for broadening participation through research.

Q: How would the spectraMRR instrument complement the nanoMRR in your research? 

Dr. Twagirayezu: The nanoMRR has been essential for our work here at Lamar University and we are now seeking to acquire a spectraMRR  because of its additional capabilities. The nanoMRR operates in 18- 26 GHz, which is ideal for the analysis of small molecules. The spectraMRR, on the other hand, operates from 4 to 18 GHz and includes both cavity enhancement and broadband capabilities. These characteristics make it more suitable for the characterization of larger molecules in complex mixtures, allowing us to expand our research beyond what the nanoMRR can do.

So, they complement each other: the nanoMRR is a great tool for small molecules, while the spectraMRR can handle larger molecules and more complex samples. Having both would allow us to study a wider range of substances, potentially attracting more grants and enabling us to justify new research applications.

 Q: Are there challenges in using MRR or rotational spectroscopy in general?  

Dr. Twagirayezu : The biggest challenge is dealing with rotational patterns of the unknown. It can be overwhelming when students try to analyze such rich data. For students who are eager to learn, we can guide them through it, but it’s a lengthy process that requires minimal training in rotational spectroscopy. I think, BrightSpec could expand on ways to make it easier for people who lack a background in rotational spectroscopy, particularly when analyzing unknowns. From what I understand, that’s a major task that the Bright Spec team is working on these days.

 Q: What would you tell a fellow professor about using MRR or the nanoMRR instrument?  

Dr. Twagirayezu : MRR is unique and it stands out as a spectroscopic technique capable of analyzing multiple analytes in a mixture without the need for chromatographic separation. As I said before, the key advantages over other conventional techniques include chemical specificity, formation richness, and fast experimental measurements. I would also recommend it as a pedagogical tool for teaching molecular spectroscopy. This instrument can help illustrate the fundamentals of high-resolution spectroscopy in a way that students can appreciate it.