{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/35201"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/35201","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Semi-Packed Micro Gas Chromatography Columns","abstract":"Separation of complex gaseous mixtures using gas chromatography (GC) is an important step in analytical systems for environmental monitoring, medical diagnosis, and forensic science. Due to its high resolving power, analysis speed, and small sample size, GC, has become the premier technique for separation and analysis of volatile and semi-volatile organic compounds. Miniaturization of analytical systems has become a major trend which is mainly driven by advancements in microfabrication techniques and a need for portable lab-on-a-chip systems for onsite monitoring. Microfabricated columns have been explored for applications in analytical processes like GC in several research studies. These microGC columns typically have open rectangular or open circular cross sections which is a result of the etching process utilized in the fabrication. This work reports the fabrication and performance of a new generation of silicon-on-glass micro-electro-mechanical systems (MEMS) based GC columns with microposts namely \"semi-packed.\" These columns can be fabricated on a 2 cm2-die for a 1 m-long channel or a 1 cm2-die for a 25 cm-long channel. The semi-packed columns have a higher sample capacity as the overall surface area is larger than that of open rectangular columns of the same dimensions. The separation efficiency of these columns is also superior to that of open columns due to the presence of the microposts. As compared to conventional packed columns, the semi-packed columns show lower pressure drops and a more uniform flow profile, both of which contribute to, performance in terms of separation efficiency.","abstract_html":"Separation of complex gaseous mixtures using gas chromatography (GC) is an important step in analytical systems for environmental monitoring, medical diagnosis, and forensic science. Due to its high resolving power, analysis speed, and small sample size, GC, has become the premier technique for separation and analysis of volatile and semi-volatile organic compounds. Miniaturization of analytical systems has become a major trend which is mainly driven by advancements in microfabrication techniques and a need for portable lab-on-a-chip systems for onsite monitoring. Microfabricated columns have been explored for applications in analytical processes like GC in several research studies. These microGC columns typically have open rectangular or open circular cross sections which is a result of the etching process utilized in the fabrication. This work reports the fabrication and performance of a new generation of silicon-on-glass micro-electro-mechanical systems (MEMS) based GC columns with microposts namely "semi-packed." These columns can be fabricated on a 2 cm2-die for a 1 m-long channel or a 1 cm2-die for a 25 cm-long channel. The semi-packed columns have a higher sample capacity as the overall surface area is larger than that of open rectangular columns of the same dimensions. The separation efficiency of these columns is also superior to that of open columns due to the presence of the microposts. As compared to conventional packed columns, the semi-packed columns show lower pressure drops and a more uniform flow profile, both of which contribute to, performance in terms of separation efficiency.","abstract_has_math":false,"creators":["Ali, Syed Aftab"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical and Computer Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Agah, Masoud"],"committee_members":["Ashraf-Khorassani, Medhi","Hendricks, Robert W."],"year":2008,"date_issued":"2008-09-12","date_published":"2008-09-12","updated_at":"2026-07-22T22:19:16Z","subjects":["MicroGC","Separation Columns","MEMS","Gas chromatography","Micro Analytical Systems"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-09262008-142100"],"render_values":[{"text":"etd-09262008-142100","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/35201","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Agah, Masoud"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Ashraf-Khorassani, Medhi","Hendricks, Robert W."]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Ali, Syed Aftab"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:46:00Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:46:00Z","2010-12-22"]},{"key":"dc:date.issued","label":"Date","values":["2008-09-12"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["MicroGC","Separation Columns","MEMS","Gas chromatography","Micro Analytical Systems"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-09262008-142100"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/35201"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Separation of complex gaseous mixtures using gas chromatography (GC) is an important step in analytical systems for environmental monitoring, medical diagnosis, and forensic science. Due to its high resolving power, analysis speed, and small sample size, GC, has become the premier technique for separation and analysis of volatile and semi-volatile organic compounds. Miniaturization of analytical systems has become a major trend which is mainly driven by advancements in microfabrication techniques and a need for portable lab-on-a-chip systems for onsite monitoring. Microfabricated columns have been explored for applications in analytical processes like GC in several research studies. These microGC columns typically have open rectangular or open circular cross sections which is a result of the etching process utilized in the fabrication. This work reports the fabrication and performance of a new generation of silicon-on-glass micro-electro-mechanical systems (MEMS) based GC columns with microposts namely \"semi-packed.\" These columns can be fabricated on a 2 cm2-die for a 1 m-long channel or a 1 cm2-die for a 25 cm-long channel. The semi-packed columns have a higher sample capacity as the overall surface area is larger than that of open rectangular columns of the same dimensions. The separation efficiency of these columns is also superior to that of open columns due to the presence of the microposts. As compared to conventional packed columns, the semi-packed columns show lower pressure drops and a more uniform flow profile, both of which contribute to, performance in terms of separation efficiency."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Semi-Packed Micro Gas Chromatography Columns"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Agah, Masoud"],"dc:contributor.committeemember":["Ashraf-Khorassani, Medhi","Hendricks, Robert W."],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["Ali, Syed Aftab"],"dc:date.accessioned":["2014-03-14T20:46:00Z"],"dc:date.available":["2014-03-14T20:46:00Z","2010-12-22"],"dc:date.issued":["2008-09-12"],"dc:description.abstract":["Separation of complex gaseous mixtures using gas chromatography (GC) is an important step in analytical systems for environmental monitoring, medical diagnosis, and forensic science. Due to its high resolving power, analysis speed, and small sample size, GC, has become the premier technique for separation and analysis of volatile and semi-volatile organic compounds. Miniaturization of analytical systems has become a major trend which is mainly driven by advancements in microfabrication techniques and a need for portable lab-on-a-chip systems for onsite monitoring. Microfabricated columns have been explored for applications in analytical processes like GC in several research studies. These microGC columns typically have open rectangular or open circular cross sections which is a result of the etching process utilized in the fabrication. This work reports the fabrication and performance of a new generation of silicon-on-glass micro-electro-mechanical systems (MEMS) based GC columns with microposts namely \"semi-packed.\" These columns can be fabricated on a 2 cm2-die for a 1 m-long channel or a 1 cm2-die for a 25 cm-long channel. The semi-packed columns have a higher sample capacity as the overall surface area is larger than that of open rectangular columns of the same dimensions. The separation efficiency of these columns is also superior to that of open columns due to the presence of the microposts. As compared to conventional packed columns, the semi-packed columns show lower pressure drops and a more uniform flow profile, both of which contribute to, performance in terms of separation efficiency."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-09262008-142100"],"dc:identifier.uri":["http://hdl.handle.net/10919/35201"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["MicroGC","Separation Columns","MEMS","Gas chromatography","Micro Analytical Systems"],"dc:title":["Semi-Packed Micro Gas Chromatography Columns"],"dc:type":["Thesis"],"thesis:degree_discipline":["Electrical and Computer Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:16Z"}