Microfabricated planar glass gas chromatography with photoionization detection

Lewis, Alastair C.; Hamilton, Jacqueline F.; Rhodes, Christopher N.; Halliday, Jaydene; Bartle, Keith D.; Homewood, Philip; Grenfell, Robin J.P.; Goody, B A; Harling, Alice M.; Brewer, Paul J.; Vargha, Gergely; Milton, Martin

doi:10.1016/j.chroma.2009.12.009

Cited by 57 publications

(26 citation statements)

References 24 publications

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“…Therefore, the PI technique has been used as a convenient method for detecting stable neutral compounds such as volatile organic compounds or neutral oil components [2, 3, 6, 7, 9]. …”

Section: Resultsmentioning

confidence: 99%

“…After their discovery, PI received very little attention from the scientific community. However, in 2010, interest in PI was reignited with the description of the attachment of PI detection to “microfabricated planar glass GC”; the detection limit of mono-aromatics was sub-ng on columns [2]. A similar connection of PI to a portable GC system reported in 2013 showed a low detection limit less than 5 ppb for volatile organic compounds such as benzene, toluene, and styrene [3].…”

Section: Introductionmentioning

confidence: 99%

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Analysis of 62 synthetic cannabinoids by gas chromatography–mass spectrometry with photoionization

2016

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Gas chromatography–mass spectrometry (GC–MS) in electron ionization (EI) mode is one of the most commonly used techniques for analysis of synthetic cannabinoids, because the GC–EI-MS spectra contain characteristic fragment ions for identification of a compound; however, the information on its molecular ions is frequently lacking. To obtain such molecular ion information, GC–MS in chemical ionization (CI) mode is frequently used. However, GC–CI-MS requires a relatively tedious process using reagent gas such as methane or isobutane. In this study, we show that GC–MS in photoionization (PI) mode provided molecular ions in all spectra of 62 synthetic cannabinoids, and 35 of the 62 compounds showed only the molecular radical cations. Except for the 35 compounds, the PI spectra showed very simple patterns with the molecular peak plus only a few fragment peak(s). An advantage is that the ion source for GC–PI-MS can easily be used for GC–EI-MS as well. Therefore, GC–EI/PI-MS will be a useful tool for the identification of synthetic cannabinoids contained in a dubious product. To the best of our knowledge, this is the first report to use GC–PI-MS for analysis of synthetic cannabinoids.

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“…Therefore, the PI technique has been used as a convenient method for detecting stable neutral compounds such as volatile organic compounds or neutral oil components [2, 3, 6, 7, 9]. …”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of 62 synthetic cannabinoids by gas chromatography–mass spectrometry with photoionization

2016

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“…32 Glass has been used in applications ranging from capillary electrophoresis 33 to polymerase chain reactions (PCR) 34 and to gas chromatographs. 35 Hybrid silicon-glass, silicon-polymer, or glass-polymer devices can be made, but the differences in material properties need to be understood. For example, in a comparison of capillary electrophoresis chips made of single materials vs. bonded dissimilar materials, the singlematerial devices performed better.…”

Section: The Remaining Advantages Of Silicon and Glassmentioning

confidence: 99%

A practical guide for the fabrication of microfluidic devices using glass and silicon

Iliescu¹,

Taylor²,

Avram³

et al. 2012

Biomicrofluidics

302

207

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This paper describes the main protocols that are used for fabricating microfluidic devices from glass and silicon. Methods for micropatterning glass and silicon are surveyed, and their limitations are discussed. Bonding methods that can be used for joining these materials are summarized and key process parameters are indicated. The paper also outlines techniques for forming electrical connections between microfluidic devices and external circuits. A framework is proposed for the synthesis of a complete glass/silicon device fabrication flow. I. WHY USE SILICON AND GLASS IN MICRO-AND NANO-FLUIDIC APPLICATIONS?Micro-and nano-fluidic technology continues to be embraced by biologists, 1-3 chemists, 4 and engineers throughout academia and industry. As its applications have expanded, there has been an explosion in the range of materials and processes used to fabricate these devices. The earliest microfluidic devices (e.g., gas 5 and liquid 6 chromatography devices) were made from silicon and glass and borrowed processes directly from semiconductor and microelectromechanical systems (MEMS) manufacturing. 7 Now, however, many researchers have moved away from silicon and glass, and instead use cast elastomers such as polydimethylsiloxane (PDMS)-which is ideal for swift prototyping-or thermoplastic polymers, which can be hot-embossed or injection-molded and are well suited to inexpensive manufacturing. Yet, there remain many applications where glass and silicon offer advantages over polymeric materials. In this paper, we highlight these advantages and offer a framework for selecting fabrication processes when using silicon and glass. A. The dominance of soft lithographyOver the last decade, PDMS has become virtually the default material for forming microfluidic devices, 8 because of the sheer ease with which it can be cast on to a micro-scale mould and then strongly bonded to glass. 9 The elastomeric nature of the material has been exploited to integrate fluidic valves and pumps on-chip and has simplified the production of multi-layer devices because the soft layers readily conform to each other. 10,11 Yet, the low stiffness (usually <1 MPa) of PDMS relative to amorphous thermoplastics, silicon, and glass has its own a) Authors to whom correspondence should be addressed. Electronic addresses: ciliescu@ibn.a-star.edu.sg and hkt@ntu.edu.sg. 6, 016505 (2012) drawbacks. High aspect-ratio channels are notoriously difficult to fabricate in PDMS because of their propensity to collapse. 12 Moreover, difficulties in automating the handling of such a soft material have hampered efforts to scale up PDMS device manufacturing. Meanwhile, PDMS's high oxygen and water permeabilities have proved both a blessing and a curse in different applications.The hydrophobic nature of PDMS can be an important consideration for some biological applications. In drug screening applications, for example, hydrophobic drugs as well as metabolites (urea or albumin) can be absorbed into the device's material due to hydrophobic--hydrophobic interaction...

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“…The study of semiochemicals, for example, pheromones, involves the use of live detectors, in which the antenna of an insect is part of an electronic circuit which provides a highly specific signal to the pheromones relevant to that insect species (D'Alessandro & Turlings, 2006). Unsaturated and aromatic molecules may be differentiated from other mixture components when the photoionization (PI) detector is used (Lewis et al, 2010). Chemiluminiscense detectors are highly sensitive and selective to nitrogen-or suphur-containing substances (Shearer, 1992).…”

Section: Detection Systemsmentioning

confidence: 99%