A High Performance Hand-Held Gas Chromatograph

Yu, Conrad M.; Lucas, M. S.; Koo, Jachoon; Stratton, Paul; Delima, Terri L.; Behymer, Elaine

doi:10.1115/imece1998-1288

Cited by 9 publications

(10 citation statements)

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“…Several laboratories are working on the development of microfabricated columns for gas chromatography. − These columns are attractive because of their small size, low thermal mass allowing rapid temperature programming with relatively low power, and parallel manufacturing, which should result in low production costs. These attributes make these devices attractive for a number of applications involving on-site monitoring of environmental samples.…”

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confidence: 99%

“…Most microfabricated column designs have used silicon microelectromechanical system (MEMS) technologies for column fabrication. Gas-phase reactive ion etching produces high-quality rectangular channels in silicon wafer substrates. ,,− After etching, the open channels are sealed with Pyrex glass anodically bonded to the silicon surface. Back etching of the silicon substrate is used to remove excess substrate to further reduce thermal mass .…”

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confidence: 99%

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High-Performance, Static-Coated Silicon Microfabricated Columns for Gas Chromatography

et al. 2006

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A procedure is described for the preparation of high-performance etched silicon columns for gas chromatography. Rectangular channels, 150 mum wide by 240 mum deep are fabricated in silicon substrates by gas-phase reactive ion etching. A 0.1-0.2-mum-thick film of dimethyl polysiloxane stationary phase is deposited on the channel walls by filling the channel with a dilute solution in 1:1 n-pentane and dichloromethane and pumping away the solvent. A thermally activated cross-linking agent is used for in situ cross-linking. A 3-m-long microfabricated column generated approximately 12 500 theoretical plates at optimal operating conditions using air as carrier gas. A kinetic model for the efficiency of rectangular cross-section columns is used to evaluate column performance. Results indicate an additional source of gas-phase dispersion beyond longitudinal diffusion and nonequilibrium effects, probably resulting from numerous turns in the gas flow path through the channel. The columns are thermally stable to at least 180 degrees C using air carrier gas. Temperature programming is demonstrated for the boiling point range from n-C5 to n-C12. A 3.0-m-long column heated at 10 degrees C/min obtains a peak capacity of over 100 peaks with a resolution of 1.18 and a separation time of approximately 500 s. With a 0.25-m-long column heated at 30 degrees C/min, a peak capacity of 28 peaks is obtained with a separation time of 150 s. Applications are shown for the analysis of air-phase petroleum hydrocarbons and the high-speed analysis of chemical warfare agent and explosive markers.

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High-Performance, Static-Coated Silicon Microfabricated Columns for Gas Chromatography

et al. 2006

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“…Miniaturized and microfabricated instruments for gas chromatography (GC) are under development in several laboratories. − These instruments are of interest because of their very small size, weight, and resource requirements and are intended for on-site analysis. Completely autonomous instruments for remote sensing will use atmospheric-pressure air as carrier gas, − two-way wireless communication, , and batteries with remote recharging capabilities.…”

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confidence: 99%

Silicon Microfabricated Column with Microfabricated Differential Mobility Spectrometer for GC Analysis of Volatile Organic Compounds

et al. 2005

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A 3.0-m-long, 150-microm-wide, 240-microm-deep channel etched in a 3.2-cm-square silicon chip, covered with a Pyrex wafer, and coated with a dimethyl polysiloxane stationary phase is used for the GC separation of volatile organic compounds. The column, which generates approximately 5500 theoretical plates, is temperature-programmed in a conventional convection oven. The column is connected through a heated transfer line to a microfabricated differential mobility spectrometer. The spectrometer incorporates a 63Ni source for atmospheric-pressure chemical ionization of the analytes. Nitrogen or air transport gas (flow 300 cm(3)/min) drives the analyte ions through the cell. The spectrometer operates with an asymmetric radio frequency (RF) electric field between a pair of electrodes in the detector cell. During each radio frequency cycle, the ion mobility alternates between a high-field and a low-field value (differential mobility). Ions oscillate between the electrodes, and only ions with an appropriate differential mobility reach a pair of biased collectors at the downstream end of the cell. A compensation voltage applied to one of the RF electrodes is scanned to allow ions with different differential mobilities to pass through the cell without being annihilated at the RF electrodes. A unique feature of the device is that both positive and negative ions are detected from a single experiment. The combined microfabricated column and detector is evaluated for the analysis of volatile organic compounds with a variety of functionalities.

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“…In the laboratory, this material is generally obtained by chemical vapor deposition and other methods. Graphene oxide (GO) has a large specific surface area, but its structure is imperfect compared with intrinsic graphene, which is mainly reflected in unpaired electrons, so it is likely to combine with gas molecules [ 6 ]. Besides, there are many oxygen-containing functional groups in the microstructure of GO, which is the reason why it has a large specific surface area and strong adsorption capacity.…”

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confidence: 99%

Double-UV Photoionizaion Detector with Graphene Oxide-Coated Electrodes

Zhou

Zhang

et al. 2022

Applied Bionics and Biomechanics

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The structure of a photoionization detector was optioned and researched. In order to solve the problem of the photoionization detector’ lamp surface residue interference, a new structure of the self-cleaning double-UV detector was adopted. At the same time, the air flow field of the detector was simulated by the finite element method. Through analyzing the results of the simulation experiment, further optimization of the gas channel for the microdetector was carried out, and the ionization chamber with axial flow structure was finally chosen. The new nanomaterial, graphene oxide was used to modify the surface of the collector plate of detector to improve the gas sensitivity and sensitivity of the photoionization detector. Through the experimental analysis, the performance indexes of detector were described in detail. The minimum detection limit of the detector is 2.5 × 10 − 7 . The linearity response of the detector was analyzed, and the linear correlation coefficient reaches 0.993. The experimental results show that the double-UV detector can improve the overall gas sensing characteristics and provide an ideal detection unit for volatile organic compound (VOC) gas detection.

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A High Performance Hand-Held Gas Chromatograph

Cited by 9 publications

References 0 publications

High-Performance, Static-Coated Silicon Microfabricated Columns for Gas Chromatography

High-Performance, Static-Coated Silicon Microfabricated Columns for Gas Chromatography

Silicon Microfabricated Column with Microfabricated Differential Mobility Spectrometer for GC Analysis of Volatile Organic Compounds

Double-UV Photoionizaion Detector with Graphene Oxide-Coated Electrodes

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