Author: Carlos R. Vilorio
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low thermal mass interface with the chip, while a silk screen method is demonstrated for easy printing of heaters. Chromatogram results are shown in both Temperature Program and Thermal Gradient runs.
Gas Chromatography Micro-chip with High Temperature Interface and Silk Screen Heaters
Author: Carlos R. Vilorio
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low thermal mass interface with the chip, while a silk screen method is demonstrated for easy printing of heaters. Chromatogram results are shown in both Temperature Program and Thermal Gradient runs.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low thermal mass interface with the chip, while a silk screen method is demonstrated for easy printing of heaters. Chromatogram results are shown in both Temperature Program and Thermal Gradient runs.
Microchip Thermal Gradient Gas Chromatography
Author: Anzi Wang
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 143
Book Description
Although the airbath oven is a reliable heating method for gas chromatography (GC), resistive heating is needed for higher analytical throughput and on-site chemical analysis because of size, heating rate and power requirements. In the last thirty years, a variety of resistive heating methods were developed and implemented for both benchtop and portable GC systems. Although fast heating rates and low power consumption have been achieved, losses in column efficiency and resolution, complex construction processes and difficulties experienced in recovering damaged columns have also become problematic for routine use of resistively heated columns. To solve these problems, a new resistively heated column technique, which uses metal columns and self-insulated heating wires, was developed for capillary gas chromatography. With this method, the total thermal mass was significantly less than in commercial column assemblies. Temperature-programming using resistive heating was at least 10 times faster than with a conventional oven, while only consuming 1−5% of the power that an oven would use. Cooling a column from 350 °C to 25 °C with an air fan only required 1.5 min. Losses in column efficiency and peak capacity were negligible when compared to oven heating. The major trade-off was slightly worse run-to-run retention time deviations, which were still acceptable for most GC analyses. The resistively heated column bundle is highly suitable for fast GC separations and portable GC instruments.
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 143
Book Description
Although the airbath oven is a reliable heating method for gas chromatography (GC), resistive heating is needed for higher analytical throughput and on-site chemical analysis because of size, heating rate and power requirements. In the last thirty years, a variety of resistive heating methods were developed and implemented for both benchtop and portable GC systems. Although fast heating rates and low power consumption have been achieved, losses in column efficiency and resolution, complex construction processes and difficulties experienced in recovering damaged columns have also become problematic for routine use of resistively heated columns. To solve these problems, a new resistively heated column technique, which uses metal columns and self-insulated heating wires, was developed for capillary gas chromatography. With this method, the total thermal mass was significantly less than in commercial column assemblies. Temperature-programming using resistive heating was at least 10 times faster than with a conventional oven, while only consuming 1−5% of the power that an oven would use. Cooling a column from 350 °C to 25 °C with an air fan only required 1.5 min. Losses in column efficiency and peak capacity were negligible when compared to oven heating. The major trade-off was slightly worse run-to-run retention time deviations, which were still acceptable for most GC analyses. The resistively heated column bundle is highly suitable for fast GC separations and portable GC instruments.
Publications of the National Institute of Standards and Technology ... Catalog
Author: National Institute of Standards and Technology (U.S.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 648
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 648
Book Description
NBS Special Publication
Author:
Publisher:
ISBN:
Category : Weights and measures
Languages : en
Pages : 668
Book Description
Publisher:
ISBN:
Category : Weights and measures
Languages : en
Pages : 668
Book Description
Publications of the National Bureau of Standards ... Catalog
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 668
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 668
Book Description
Microchip Capillary Electrophoresis
Author: Charles Henry
Publisher: Humana
ISBN: 9781588292933
Category : Science
Languages : en
Pages : 238
Book Description
Leading chemists and engineers concisely explain the principles behind microchip capillary electrophoresis and demonstrate its use in a variety of biochemical applications, ranging from the analysis of DNA, proteins, and peptides to single cell analysis and measuring the impact of surface modification on flow in microfluidic channels. Since surface chemistry must be carefully considered for optimal operation at this scale, the authors also discuss methods of both adsorbed and covalent surface modification for its control. Fabrication methods for producing microchips with glass, poly(dimethylsiloxane), and other polymers are also provided so that even novices can produce simple devices for standard separations. Microchip Capillary Electrophoresis: Methods and Protocols provides a practical starting point for either initiating research in the field of microchip capillary electrophoresis or understanding the full range of what can be done with existing systems.
Publisher: Humana
ISBN: 9781588292933
Category : Science
Languages : en
Pages : 238
Book Description
Leading chemists and engineers concisely explain the principles behind microchip capillary electrophoresis and demonstrate its use in a variety of biochemical applications, ranging from the analysis of DNA, proteins, and peptides to single cell analysis and measuring the impact of surface modification on flow in microfluidic channels. Since surface chemistry must be carefully considered for optimal operation at this scale, the authors also discuss methods of both adsorbed and covalent surface modification for its control. Fabrication methods for producing microchips with glass, poly(dimethylsiloxane), and other polymers are also provided so that even novices can produce simple devices for standard separations. Microchip Capillary Electrophoresis: Methods and Protocols provides a practical starting point for either initiating research in the field of microchip capillary electrophoresis or understanding the full range of what can be done with existing systems.
Semiconductor Gas Sensors
Author: Raivo Jaaniso
Publisher: Woodhead Publishing
ISBN: 0081025602
Category : Technology & Engineering
Languages : en
Pages : 512
Book Description
Semiconductor Gas Sensors, Second Edition, summarizes recent research on basic principles, new materials and emerging technologies in this essential field. Chapters cover the foundation of the underlying principles and sensing mechanisms of gas sensors, include expanded content on gas sensing characteristics, such as response, sensitivity and cross-sensitivity, present an overview of the nanomaterials utilized for gas sensing, and review the latest applications for semiconductor gas sensors, including environmental monitoring, indoor monitoring, medical applications, CMOS integration and chemical warfare agents. This second edition has been completely updated, thus ensuring it reflects current literature and the latest materials systems and applications. - Includes an overview of key applications, with new chapters on indoor monitoring and medical applications - Reviews developments in gas sensors and sensing methods, including an expanded section on gas sensor theory - Discusses the use of nanomaterials in gas sensing, with new chapters on single-layer graphene sensors, graphene oxide sensors, printed sensors, and much more
Publisher: Woodhead Publishing
ISBN: 0081025602
Category : Technology & Engineering
Languages : en
Pages : 512
Book Description
Semiconductor Gas Sensors, Second Edition, summarizes recent research on basic principles, new materials and emerging technologies in this essential field. Chapters cover the foundation of the underlying principles and sensing mechanisms of gas sensors, include expanded content on gas sensing characteristics, such as response, sensitivity and cross-sensitivity, present an overview of the nanomaterials utilized for gas sensing, and review the latest applications for semiconductor gas sensors, including environmental monitoring, indoor monitoring, medical applications, CMOS integration and chemical warfare agents. This second edition has been completely updated, thus ensuring it reflects current literature and the latest materials systems and applications. - Includes an overview of key applications, with new chapters on indoor monitoring and medical applications - Reviews developments in gas sensors and sensing methods, including an expanded section on gas sensor theory - Discusses the use of nanomaterials in gas sensing, with new chapters on single-layer graphene sensors, graphene oxide sensors, printed sensors, and much more
Publications of the National Bureau of Standards, 1979 Catalog
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 650
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 650
Book Description
Publications
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 668
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 668
Book Description
Chemical Engineering Equipment Buyers' Guide
Author:
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 856
Book Description
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 856
Book Description