Manuel Manard’s Mass-Selective Photoionization Detector

Multiple government agencies are interested in field-portable instruments for real-time chemical analysis and detection. Although technology already exists for real-time chemical analysis, the two types available pose distinct challenges: the large instruments are too big for easy in-field deployment, and the small sensors lack the necessary specificity in the data they collect. With these existing technologies, there is always a tradeoff between size and performance. To that end, principal investigator Manuel Manard set out to meet the needs of government agencies in his fiscal year (FY) 2024 Site-Directed Research and Development (SDRD) project by creating a field-portable instrument that is small, inexpensive, ruggedized, and can be deployed by both humans and drones.

To do this, Manuel and his team worked to design, build, and test a portable proof-of-concept instrument that couples a photoionization (PI) lamp with an array of ion traps to provide mass spectra of chemical species in real time. The PI detectors help to mitigate the lack of specific data of existing instruments, but they are only able to inform the user if a chemical with an ionization potential less than or equal to the UV photon energy is present. To provide the selectivity that the PI lamps lack, Manuel couples them with mass analyzers. Recent advances have been made to reduce the size of mass analyzers, meaning that they can now be used to achieve analytical specificity in the field. By combining PI lamps with newly downsized mass analyzers, Manuel and his team can achieve both sensitivity and selectivity for in-field chemical
analysis.

As a result of this SDRD effort, a printed circuit board (PCB) containing an array of 25 ion traps, with diameters of 500 μm, was designed and fabricated. The PCB measures 1 inch in diameter and 0.0625 inches thick—small but mighty! This proof-of-concept instrument couples a PI lamp with a Paul-type ion trap to provide mass spectra of chemical species. Data was acquired that showed the presence of ions, generated by the PI lamp, confined in the trap, and Manuel and his team saw a 20x increase in trapped ion signal strength.

Overall, Manuel’s success in this project is a significant achievement toward in-field chemical analysis. With additional development, this concept could serve as the foundation for a fieldable, real-time chemical sensor for field experimentation conducted at the NNSS and for first responders.

We congratulate Manuel and his team on a job well done!