Modular GC: A Fully Integrated Micro Gas Chromatography System

TR Number



Journal Title

Journal ISSN

Volume Title


Virginia Tech


Gas Chromatography (GC) is one of the most important and widely used tools in analytical chemistry. However, they are bulky, have a longer measurement cycle, and consume a high amount of power. Micro-Gas Chromatography (µGC) is portable and energy-efficient, which allows onsite, real-time biological, forensic, and environmental analyses. This thesis presents a ready-to-deploy implementation of microfabricated gas chromatography (µGC) system capable of separating complex samples. We describe robust, modular, and scalable hardware and software architecture based on Real-Time Operating System (RTOS) and Python Graphical User Interface (GUI) integrated with various microfabricated devices to realize a fully functional µGC system. A sample heater for headspace injection, microfabricated separation column (µSC), a Photoionization Detector (PI-D), and a flow controller unit are integrated with the modular hardware and software to realize a fully functional Vacuum Outlet µGC system. We have designed a novel auto-calibration method for temperature calibration of the microfabricated devices which does not require changing the electronic circuitry or reprogramming the device. The vacuum outlet µGC setup is tested with various mixture of analytes. For these experiments, an average relative standard deviation (RSD) for retention time repeatability of 2.5% is achieved. Data processing techniques for raw chromatograms, including baseline correction and peak detection, are implemented on a microcontroller board and tested extensively as a part of this work. A novel algorithm for multidimensional analysis for the identification of co-eluting compounds in complex samples is implemented with a prediction accuracy of 94%.



Micro Gas Chromatography, Embedded Systems, Data Analysis