Through the years with on-a-chip gas chromatography: a review

Abstract

In recent years, the need for measurement and detection of samples in situ or with very small volume and low concentration (low and sub-parts per billion) is a cause for miniaturizing systems via microelectromechanical system (MEMS) technology. Gas chromatography (GC) is a common technique that is widely used for separating and measuring semi-volatile and volatile compounds. Conventional GCs are bulky and cannot be used for in situ analysis, hence in the past decades many studies have been reported with the aim of designing and developing chip-based GC. The focus of this review is to follow and investigate the development and the achievements in the field of chip-based GC and its components from the beginning up to the present.

Diagnosis of pulmonary tuberculosis and assessment of treatment response through analyses of volatile compound patterns in exhaled breath samples

“…The performance of the classification model based on k-NN is shown in Table 2. An optimal model limited to 8 neighbors was selected as a result of a leave-one-out cross validation procedure (15). Sensitivity was estimated at 94.1% (95% confidence interval [CI], 83.8-98.8%) and specificity was 90.0% (95% CI, 68.3-98.8%).…”

“…However, such approaches are limited by technical complexity, high costs, and the need for pre-processing of the samples before testing. In spite of recent advances in miniaturization, GC–MS technology is still not mobile and cannot perform real-time measurements, making it not suitable for point-of-care use (15). Alternatively, VOC analysis could be aimed at identifying the composite, unique signal resulting from the exposure of a complex mixture of VOCs to arrays of sensors (also called “electronic noses”) (16, 17).…”

Fabrication of anti-protein-fouling poly(ethylene glycol) microfluidic chip electrophoresis by sandwich photolithography

“…Since the first demonstration in 1990, 1,2 microfluidic chip electrophoresis (MCE), as a highly integrated and automated portable device, has been developed rapidly with important applications in many areas such as life science, biology, medicine, food, and environmental monitoring, [3][4][5][6][7] where entire chemical and bio-analyses in miniaturized volumes are performed with high sensitivities and efficencies. [8][9][10][11][12][13][14] Organic materials such as polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA) have been used to fabricate MCE. 15,16 Compared with inorganic materials, polymers are flexible and inexpensive, and therefore, have become the most commonly used microchip materials.…”

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

“…[3][4][5][6][7][8][9][10][11][12] Besides, the MCE has great potential because of its miniaturization, integration, and automation. [13][14][15][16][17][18] In terms of the current research for MCE and related technology, there still exist a lot of challenges. For example, the separation voltage of conventional microchip electrophoresis is generally a few hundred volts to several kilovolts.…”