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Dissertation Defense

Advancements of micro gas chromatographs and their core components

Max Li

Passcode: 660721


The development of portable vapor sensors is of high interest for in situ on-site and real-time chemical analysis, which would allow for industrial and environmental monitoring as well as point-of-care applications. Advances in microelectromechanical systems (MEMS) technologies has allowed for the miniaturization of benchtop gas chromatography (GC) into portable micro GC (µGC) systems that allow for field analysis. This dissertation details the development of critical µGC components, especially microcolumns and micro photoionization detectors (PIDs), along with their assembly into prototype µGC systems. Two different microcolumn coatings were developed to broaden the range of chemical separations suitable for µGC analysis, while a new column coating method was demonstrated to improve separation performance. A micro helium desorption PID (µHDPID) fabrication process was developed to allow for the robust fabrication of universal vapor detectors, complementing the increased range of separations from the new microcolumn coatings. A high sensitivity PID system was also assembled using miniaturized GC components and demonstrated sub-pg detection limits, comparable to that of benchtop flame ionization detectors. Together, these developments increase the range of applications that can be targeted by µGC by broadening its separation and detection capabilities, as well as improving the sensing performance.

Chair: Professor Sherman Fan