Sigma Xi Poster Competition
Determination of Conditions for a Portable Ion Mobility Spectrometer
Academic Level at Time of Presentation
Senior
Major
Chemistry
Minor
Mathematics
List all Project Mentors & Advisor(s)
Dr. Caleb Morris
Presentation Format
Event
Abstract/Description
Portable spectrometers are used in detection of explosives, drugs, and chemical warfare agents. Ion mobility spectrometry (IMS) lends itself well to this detection due to rapid separation on the order of milliseconds in a small device footprint. It separates based on a compound’s size to charge ratio through collisions with a buffer gas. High resolution is desired to minimize false positives. Typically, this is achieved by increasing the number of collisions between the buffer gas and analyte through lengthening the analysis region. As a result, portable devices are typically limited in their resolution due to size constraints. Alternative methods must be found to achieve high resolution devices. Trapped ion mobility spectrometry (TIMS) differs from other IMS separation methods by achieving a greater number of gas collisions through trapping of the ions followed by slow elution. This results in a small analysis region. However, traditional TIMS devices use heavy brass electrodes and pumps. Here, a TIMS analysis region is developed that allows for lightweight printed circuit board electrodes and smaller, lightweight pumps to achieve separation in a device suitable for portable, high-resolution IMS. Gas flows in the device are modeled with computation fluid dynamics while ion trajectories under these conditions are modeled with SIMION software. The results show the potential applicability of TIMS in portable spectrometers.
Spring Scholars Week 2025
Sigma Xi Poster Competition
Determination of Conditions for a Portable Ion Mobility Spectrometer
Portable spectrometers are used in detection of explosives, drugs, and chemical warfare agents. Ion mobility spectrometry (IMS) lends itself well to this detection due to rapid separation on the order of milliseconds in a small device footprint. It separates based on a compound’s size to charge ratio through collisions with a buffer gas. High resolution is desired to minimize false positives. Typically, this is achieved by increasing the number of collisions between the buffer gas and analyte through lengthening the analysis region. As a result, portable devices are typically limited in their resolution due to size constraints. Alternative methods must be found to achieve high resolution devices. Trapped ion mobility spectrometry (TIMS) differs from other IMS separation methods by achieving a greater number of gas collisions through trapping of the ions followed by slow elution. This results in a small analysis region. However, traditional TIMS devices use heavy brass electrodes and pumps. Here, a TIMS analysis region is developed that allows for lightweight printed circuit board electrodes and smaller, lightweight pumps to achieve separation in a device suitable for portable, high-resolution IMS. Gas flows in the device are modeled with computation fluid dynamics while ion trajectories under these conditions are modeled with SIMION software. The results show the potential applicability of TIMS in portable spectrometers.