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Chemical Micro Preconcentrators Development for Micro Gas Chromatography Systems

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dc.contributor.authorAlfeeli, Bassamen
dc.contributor.committeechairAgah, Masouden
dc.contributor.committeememberTaylor, Larry T.en
dc.contributor.committeememberHendricks, Robert W.en
dc.contributor.committeememberWang, Anboen
dc.contributor.committeememberMeehan, Kathleenen
dc.contributor.departmentElectrical and Computer Engineeringen
dc.date.accessioned2014-03-14T20:17:27Zen
dc.date.adate2010-11-29en
dc.date.available2014-03-14T20:17:27Zen
dc.date.issued2010-10-06en
dc.date.rdate2010-11-29en
dc.date.sdate2010-10-18en
dc.description.abstractMicroelectromechanical systems (MEMS) technology allows the realization of mechanical parts, sensors, actuators and electronics on silicon substrate. An attractive utilization of MEMS is to develop micro instruments for chemical analysis. An example is gas chromatography (GC) which is widely used in food, environmental, pharmaceutical, petroleum/refining, forensic/security, and flavors and fragrances industries. A MEMS-based micro GC (µGC) provides capabilities for quantitative analysis of complex chemical mixtures in the field with very short analysis time and small amounts of consumables. The aim of this research effort is to enhance the sensitivity and selectivity of µGC instruments by implementing chemical amplification method known as preconcentration. A micro preconcentrator (µPC) extracts the target analytes from the sample matrix, concentrates them, and injects them into the separation column for analysis. This work resulted in the development of silicon-glass bonded chips consisting of 7 mm x 7 mm x 0.38 mm multiport cavity with thousands of embedded 3D microstructures (to achieve high surface-to-volume ratio) coated with polymeric thin film adsorbents. Deep reactive ion etching (DRIE) was the enabling technology for the realization of µPCs. Several coating methods, such as inkjet printing of polymers and polymer precipitation from solution have been utilized to coat complex geometrical structures. One major outcome was the development of cobweb adsorbent structure. Moreover, the porous polymeric adsorbent Tenax TA in the film form was characterized, for the first time, for μPC application and shown to have similar properties to that of the granular form. Several μPC designs were experimentally evaluated for their performance in concentrating volatile organic compounds, including cancer biomarkers, Propofol (anesthetic agent), environmental pollutants, and chemical warfare simulants. The possibility of utilizing the μPCs in practical applications such breath analysis was also demonstrated.en
dc.description.degreePh. D.en
dc.identifier.otheretd-10182010-121942en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10182010-121942/en
dc.identifier.urihttp://hdl.handle.net/10919/29305en
dc.publisherVirginia Techen
dc.relation.haspartAlfeeli_B_D_2010.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectHandheld Chemical Analysisen
dc.subjectMicro Analytical Systemsen
dc.subjectBreath Analysisen
dc.subjectSample Pretreatmenten
dc.subjectMEMSen
dc.subjectTenax TA Filmsen
dc.subjectMicrofabricationen
dc.subjectDRIEen
dc.titleChemical Micro Preconcentrators Development for Micro Gas Chromatography Systemsen
dc.typeDissertationen
thesis.degree.disciplineElectrical and Computer Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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