Arrayed Integrated Photoionization Detectors for Highly Integrated Microscale Gas Chromatography Systems

PASSCODE: 020566

Field analysis of volatile organic compounds (VOCs) is of high interest to environmental and industrial monitoring, healthcare, and homeland security applications.  Microscale gas chromatographs (μGCs) provide the necessary selectivity and portability for these applications.  In state-of-the-art μGCs, the photoionization detector is one of the most widely used detectors.  This dissertation describes the investigation of arrayed integrated photoionization detectors (AiPDs), which feature coplanar electrodes that can be easily co-fabricated with other μGC components.  The electric field distribution, response characteristics, humidity resistance, and lifetime of the AiPDs have been investigated.

The AiPDs are monolithically integrated into a 40.3 × 55.7 mm² μGC chip with a multisensing progressive cellular architecture (MPCA).  The MPCA consists of 3 μGC cells, each of which incorporates a preconcentrator, a separation column, and 3 complementary detectors (including two different capacitive detectors and an AiPD).  Using the MPCA chip, representative analysis is experimentally demonstrated with analytes covering a wide molecular weight range (58.2-184.4 Da).  Quantitative analysis is shown in the tens to hundreds ppb range, with detection limits reaching 0.12-4.7 ppb or 0.11-4.5 ng.

CO-CHAIRS: Professor Yogesh Gianchandani & Dr. Yutao Qin