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Enel A, Vial J, Thiébaut D, Bourlon B. Gas Digital Microfluidic Platform: Application to Highly Volatile Compound Preconcentration. Anal Chem 2022; 94:4359-4365. [PMID: 35235299 DOI: 10.1021/acs.analchem.1c05128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Digital microfluidics platforms (DMFPs) have shown their efficiency in sample handling, using elementary operations that may be combined to perform complex applications. In this article, we present a new platform for gaseous samples handling involving a two-step digital preconcentration using the miniaturized preconcentrators of the DMFP. Choosing n-pentane at very low concentrations as a model for highly volatile compounds, poorly retained on the sorbent, the DMFP allowed bypassing the limit set by the breakthrough volume by repeating an elementary operation. It enabled a 5-fold increase of preconcentration factors in comparison to a single preconcentration step and an easier monitoring of the model compound. Promising applications are expected, as this system could be adapted to most volatile compound analysis devices, including micro gas chromatographs, to replace the current single-step preconcentration systems. By switching to two-step preconcentration with a DMFP, i.e., a digital preconcentration, it would be possible to get more concentrated samples through the column for easier trace analysis.
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Affiliation(s)
- Antoine Enel
- Université Grenoble Alpes, CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38000 Grenoble, France.,UMR8231 CBI, LSABM, ESPCI Paris-CNRS, PSL Institute, 10 rue Vauquelin, 75005 Paris, France
| | - Jérôme Vial
- UMR8231 CBI, LSABM, ESPCI Paris-CNRS, PSL Institute, 10 rue Vauquelin, 75005 Paris, France
| | - Didier Thiébaut
- UMR8231 CBI, LSABM, ESPCI Paris-CNRS, PSL Institute, 10 rue Vauquelin, 75005 Paris, France
| | - Bertrand Bourlon
- Université Grenoble Alpes, CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38000 Grenoble, France
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2
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Hsieh HC, Kim H. Isomer separation enabled by a micro circulatory gas chromatography system. J Chromatogr A 2020; 1629:461484. [PMID: 32889297 DOI: 10.1016/j.chroma.2020.461484] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 11/30/2022]
Abstract
Isomers, holding similar chemical and physical properties, are difficult to separate especially by utilizing a microfabricated gas chromatography system due to limited column lengths mainly imposed by low-pressure (<20 kPa) micropump capability. In this paper, we demonstrated the separation of a pair of structural isomers, isopentane and pentane, in a micro-scale gas chromatography system with a circulatory loop of two 25-cm micro open tubular columns, while operating under a minimal pressure requirement of <10 kPa. The developed micro circulatory gas chromatography (MCGC) system achieved an effective column length of 12.5 meters by circulating the isomer gases for 25 cycles, the longest micro open tubular column length ever reported by any microfabricated GC systems yet.
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Affiliation(s)
- Hao-Chieh Hsieh
- Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112 United States
| | - Hanseup Kim
- Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112 United States.
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3
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Dimandja JM. Introduction and historical background: the “inside” story of comprehensive two-dimensional gas chromatography. SEP SCI TECHNOL 2020. [DOI: 10.1016/b978-0-12-813745-1.00001-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Wang J, Nuñovero N, Nidetz R, Peterson SJ, Brookover BM, Steinecker WH, Zellers ET. Belt-Mounted Micro-Gas-Chromatograph Prototype for Determining Personal Exposures to Volatile-Organic-Compound Mixture Components. Anal Chem 2019; 91:4747-4754. [PMID: 30836745 DOI: 10.1021/acs.analchem.9b00263] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe a belt-mountable prototype instrument containing a gas chromatographic microsystem (μGC) and demonstrate its capability for near-real-time recognition and quantification of volatile organic compounds (VOCs) in moderately complex mixtures at concentrations encountered in industrial workplace environments. The μGC comprises three discrete, Si/Pyrex microfabricated chips: a dual-adsorbent micropreconcentrator-focuser for VOC capture and injection; a wall-coated microcolumn with thin-metal heaters and temperature sensors for temperature-programmed separations; and an array of four microchemiresistors with thiolate-monolayer-protected-Au-nanoparticle interface films for detection and recognition-discrimination. The battery-powered μGC prototype (20 × 15 × 9 cm, ∼2.1 kg sans battery) has on-board microcontrollers and can autonomously analyze the components of a given VOC mixture several times per hour. Calibration curves bracketing the Threshold Limit Value (TLV) of each VOC yielded detection limits of 16-600 parts-per-billion for air samples of 5-10 mL, well below respective TLVs. A 2:1 injection split improved the resolution of early eluting compounds by up to 63%. Responses and response patterns were stable for 5 days. Use of retention-time windows facilitated the chemometric recognition and discrimination of the components of a 21-VOC mixture sampled and analyzed in 3.5 min. Results from a "mock" field test, in which personal exposures to time-varying concentrations of a mixture of five VOCs were measured autonomously, agreed closely with those from a reference GC. Thus, reliable, near-real-time determinations of worker exposures to multiple VOCs with this wearable μGC prototype appear feasible.
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Affiliation(s)
- Junqi Wang
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States.,Center for Wireless Integrated MicroSensing and Systems , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Nicolas Nuñovero
- Department of Environmental Health Sciences , University of Michigan , Ann Arbor , Michigan 48109 , United States.,Center for Wireless Integrated MicroSensing and Systems , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Robert Nidetz
- Department of Mechanical Engineering , University of Michigan , Ann Arbor , Michigan 48109 , United States.,Center for Wireless Integrated MicroSensing and Systems , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Seth J Peterson
- Targeted Compound Monitoring, LLC , Beavercreek , Ohio 45440 , United States
| | - Bryan M Brookover
- Targeted Compound Monitoring, LLC , Beavercreek , Ohio 45440 , United States
| | | | - Edward T Zellers
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States.,Department of Environmental Health Sciences , University of Michigan , Ann Arbor , Michigan 48109 , United States.,Center for Wireless Integrated MicroSensing and Systems , University of Michigan , Ann Arbor , Michigan 48109 , United States
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Lara-Lbeas I, Rodríguez-Cuevas A, Andrikopoulou C, Person V, Baldas L, Colin S, Le Calvé S. Sub-ppb Level Detection of BTEX Gaseous Mixtures with a Compact Prototype GC Equipped with a Preconcentration Unit. MICROMACHINES 2019; 10:E187. [PMID: 30871284 PMCID: PMC6470503 DOI: 10.3390/mi10030187] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 11/23/2022]
Abstract
In this work, a compact gas chromatograph prototype for near real-time benzene, toluene, ethylbenzene and xylenes (BTEX) detection at sub-ppb levels has been developed. The system is composed of an aluminium preconcentrator (PC) filled with Basolite C300, a 20 m long Rxi-624 capillary column and a photoionization detector. The performance of the device has been evaluated in terms of adsorption capacity, linearity and sensitivity. Initially, PC breakthrough time for an equimolar 1 ppm BTEX mixture has been determined showing a remarkable capacity of the adsorbent to quantitatively trap BTEX even at high concentrations. Then, a highly linear relationship between sample volume and peak area has been obtained for all compounds by injecting 100-ppb samples with volumes ranging from 5⁻80 mL. Linear plots were also observed when calibration was conducted in the range 0⁻100 ppb using a 20 mL sampling volume implying a total analysis time of 19 min. Corresponding detection limits of 0.20, 0.26, 0.49, 0.80 and 1.70 ppb have been determined for benzene, toluene, ethylbenzene, m/p-xylenes and o-xylene, respectively. These experimental results highlight the potential applications of our device to monitor indoor or outdoor air quality.
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Affiliation(s)
- Irene Lara-Lbeas
- ICPEES UMR 7515, Université de Strasbourg/CNRS, F-67000 Strasbourg, France.
- Institut Clément Ader (ICA), Université de Toulouse/CNRS, INSA, ISAE-SUPAERO, Mines-Albi, UPS, 31400 Toulouse, France.
| | | | | | - Vincent Person
- In'Air Solutions, 25 rue Becquerel, 67087 Strasbourg, France.
| | - Lucien Baldas
- Institut Clément Ader (ICA), Université de Toulouse/CNRS, INSA, ISAE-SUPAERO, Mines-Albi, UPS, 31400 Toulouse, France.
| | - Stéphane Colin
- Institut Clément Ader (ICA), Université de Toulouse/CNRS, INSA, ISAE-SUPAERO, Mines-Albi, UPS, 31400 Toulouse, France.
| | - Stéphane Le Calvé
- ICPEES UMR 7515, Université de Strasbourg/CNRS, F-67000 Strasbourg, France.
- In'Air Solutions, 25 rue Becquerel, 67087 Strasbourg, France.
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Skog KM, Xiong F, Kawashima H, Doyle E, Soto R, Gentner DR. Compact, Automated, Inexpensive, and Field-Deployable Vacuum-Outlet Gas Chromatograph for Trace-Concentration Gas-Phase Organic Compounds. Anal Chem 2019; 91:1318-1327. [DOI: 10.1021/acs.analchem.8b03095] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Kate M. Skog
- Department of Chemical & Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States
| | - Fulizi Xiong
- Department of Chemical & Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States
| | - Hitoshi Kawashima
- Department of Chemical & Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States
| | - Evan Doyle
- Department of Chemical & Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States
| | - Ricardo Soto
- Department of Chemical & Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States
| | - Drew R. Gentner
- Department of Chemical & Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States
- SEARCH (Solutions for Energy, Air, Climate and Health) Center, Yale University, New Haven, Connecticut 06511, United States
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Jalal AH, Alam F, Roychoudhury S, Umasankar Y, Pala N, Bhansali S. Prospects and Challenges of Volatile Organic Compound Sensors in Human Healthcare. ACS Sens 2018; 3:1246-1263. [PMID: 29879839 DOI: 10.1021/acssensors.8b00400] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The chemical signatures of volatile organic compounds (VOCs) in humans can be utilized for point-of-care (POC) diagnosis. Apart from toxic exposure studies, VOCs generated in humans can provide insights into one's healthy and diseased metabolic states, acting as a biomarker for identifying numerous diseases noninvasively. VOC sensors and the technology of e-nose have received significant attention for continuous and selective monitoring of various physiological and pathophysiological conditions of an individual. Noninvasive detection of VOCs is achieved from biomatrices of breath, sweat and saliva. Among these, detection from sweat and saliva can be continuous in real-time. The sensing approaches include optical, chemiresistive and electrochemical techniques. This article provides an overview of such techniques. These, however, have limitations of reliability, precision, selectivity, and stability in continuous monitoring. Such limitations are due to lack of sensor stability and complexity of samples in a multivariate environment, which can lead to false readings. To overcome selectivity barriers, sensor arrays enabling multimodal sensing, have been used with pattern recognition techniques. Stability and precision issues have been addressed through advancements in nanotechnology. The use of various forms of nanomaterial not only enhance sensing performance, but also plays a major role in detection on a miniaturized scale. The rapid growth in medical Internet of Things (IoT) and artificial intelligence paves a pathway for improvements in human theranostics.
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Affiliation(s)
- Ahmed H. Jalal
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, United States
| | - Fahmida Alam
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, United States
| | - Sohini Roychoudhury
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, United States
| | - Yogeswaran Umasankar
- Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Nezih Pala
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, United States
| | - Shekhar Bhansali
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, United States
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