Using Ambient Ionization Techniques to Enable Polymer Characterization

Ambient ionization techniques are mass spectrometry (MS) methods that are designed to ionize samples at atmospheric pressure. These techniques are often characterized under three groups: 1) spray-based methods; 2) plasma-based methods; and 3) multi-mode methods (1).

Gerardo Gamez, a Professor and Graduate Advisor at Texas Tech University, leads a laboratory group that is studying the matrix effects and mechanisms encountered in ambient ionization (2). In the below video segment, Gamez highlights the power of MS for elemental, structural, and isotopic analysis, while noting that traditional sample preparation and separation steps slow down throughput. To overcome this bottleneck, Gamez discusses how his team his focusing on ambient desorption ionization (ADI) techniques, which enable direct sampling with minimal preparation. He explains how plasma-based ADI methods are particularly effective for small molecules across diverse polarities, but they struggle with large or low–vapor pressure analytes because their thermally driven desorption limits detection sensitivity (2).

Therefore, Gamez and his team looked at developing new methods to resolve these limitations (2). In their laboratory, they developed a technique called laser-assisted micro-pyrolysis sampling (LAMP). By tightly focusing a laser on specific regions of a sample, LAMP is designed to improve desorption and generate useful fragments or pyrolysis products from larger molecules, improving their identification and quantification. According to Gamez, LAMP significantly strengthens polymer analysis using plasma-based ADI.

Gamez’s group has also demonstrated multi-dimensional imaging, both lateral and depth profiling, to quantify biopolymers in lignocellulosic biomass. This approach reduces analysis time from days, using conventional wet chemistry, to mere minutes. Currently, the team is extending LAMP to even more complex polymer architectures, such as star-shaped and bottle-brush polymers, which are important for advanced technologies like drug delivery.

This interview was conducted as part of our coverage of the Winter Conference on Plasma Spectrochemistry, which is taking place from January 9–17^th in Tucson, Arizona (3).

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

References

1. The Badu Research Group, Advances in Ionization Techniques. OSU.edu. Available at: https://research.cbc.osu.edu/badu-tawiah.1/ms-techniques/introductory-ms/#:~:text=The%20ambient%20ionization%20methods%20can,Cancer%20Using%20Cheap%20Paper%20Strips (accessed 2026-01-08).
2. Texas Tech University, Dr. Gerardo Gamez. TTU.edu. Available at: https://www.depts.ttu.edu/chemistry/Faculty/gamez/ (accessed 2026-01-06).
3. IASA, Winter Conference on Plasma Spectrochemistry. IASA. Available at: https://iasa.world/winter-plasma-conference (accessed 2026-01-06).