GC-on-chip: integrated column and photoionization detector

Abstract

This paper reports a unique GC-on-chip module comprising a monolithically integrated semi-packed micro separation column (μSC) and a highly sensitive micro helium discharge photoionization detector (μDPID). While semi-packed μSC with atomic layer deposited (ALD) alumina as a stationary phase provides high separation performance, the μDPID implemented for the first time in a silicon-glass architecture inherits the desirable features of being universal, non-destructive, low power consumption (1.4 mW), and responsive. The integrated chip is 1.5 cm × 3 cm in size and requires a two-mask fabrication process. Monolithic integration alleviates the need for transfer lines between the column and the detector which improves the performance of the individual components with overall reduced fabrication and implementation costs. The chip is capable of operating under the isothermal as well as temperature and flow programming conditions to achieve rapid chromatographic analysis. The chip performance was investigated with two samples: 1) a multi-analyte gas mixture consisting of eight compounds ranging from 98 °C to 174 °C in boiling point and 2) a mixture containing higher alkanes (C9-C12). Our experiments indicate that the chip is capable of providing rapid chromatographic separation and detection of these compounds (<1 min) through the optimization of flow and temperature programming conditions. The GC-on-chip demonstrated a minimum detection limit of ~10 pg which is on a par with the widely used destructive flame ionization detector (FID).

Chip-scale gas chromatography: From injection through detection

“…Recently, there have been significant advancements in detector technology, and a wide variety of chemical detectors have been developed 13,14,[20][21][22][23][24][25][26][27] . The micro-helium discharge photoionization detector (µDPID) presented by our group has demonstrated a minimum detection limit of approximately 10 pg, which is the same as that of a flame ionization detector (FID), which is mainly used in bench-top GC systems 28 . This high sensitivity of µDPIDs reduces the system's reliance on the front-end pre-concentration step, which is typically performed to improve the detection limit of the detector.…”

“…This high sensitivity of µDPIDs reduces the system's reliance on the front-end pre-concentration step, which is typically performed to improve the detection limit of the detector. In addition, we have previously demonstrated that the µDPID can be easily integrated with the separation column and demonstrated its operation under the temperature and flow rate programming conditions 28 . These two features of µDPIDs make them a promising candidate for developing chipscale GC systems, thereby addressing the above-mentioned issues and improving the overall cost and performance of this technology.…”

Fabrication of universal serial bus flash disk type microfluidic chip electrophoresis and application for protein analysis under ultra low voltage

“…33,34 The detection limits can be further improved if more sensitive detection technique is applied. [35][36][37][38][39] Additionally, the USB flash disk type MCE makes full use of the computer USB interface, and there is no need to carry an extra cumbersome high voltage power supply. Therefore, the USB flash disk type MCE is quiet energy saving and convenient.…”

Solid-State Gas Sensors: Sensor System Challenges in the Civil Security Domain

“…Another approach at attaining extreme sensitivity is employing extremely miniaturized MEMS cantilever devices, which can detect minute changes in mass loading or temperature changes [82,83,84]. Encouraging results have also been obtained using MEMS miniaturized gas chromatography detector systems [85,86,87] and multi-parameter detector systems [88,89,90]. In principle, all these detector approaches might form interesting backend sensor solutions in the integrated particle detection systems advocated in this work.…”