title: Fabry-Pérot cavity sensor-based optofluidic gas chromatography using a microfabricated passive preconcentrator/injector.
abstract: This study reports on dual on-column Fabry-Pérot (FP) cavity sensor-based gas chromatography (GC) of mixtures of volatile organic compounds (VOCs) utilizing an on-chip device, the so called "microfabricated passive preconcentrator/injector (μPPI)". Comprehensive analysis of the sampling, desorption/injection, and compound separation performance of the μPPI-based optofluidic GC system is described. Here, the combined use of the μPPI and on-column FP cavity sensors in a common GC platform enabled diffusion-based passive sampling, rapid (<7 min) chromatographic separation, and optical detection for the quaternary VOC mixtures of benzene, TCE, toluene, and m-xylene at sub-ppm concentrations with a simpler fluidic setup than conventional GC systems. The FP cavity sensor arrangement provided the means to study the dynamics of the thermal desorption/injection of VOCs by the μPPI and its effect on the GC separation resolution. Our analysis of obtained chromatograms revealed a presence of the competitive adsorptions of VOC mixtures onto the adsorption sites of trapping materials in the μPPI, which decreased the effective sampling rate by ~50% for compounds with high volatility. The validated performance of the optofluidic GC system promises future development of a field deployable GC microsystem incorporating the μPPI and the FP cavity sensors.
authors.affiliation: Engineering Research Center for Wireless Integrated Microsensing and Systems (WIMS2), University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Seo
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Xudong
authors.initials: X
authors.lastname: Fan
authors.forename: Katsuo
authors.initials: K
authors.lastname: Kurabayashi
mesh_terms: D002138:Calibration; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005740:Gases / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D055620:Optical Phenomena; D013696:Temperature; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000302:isolation & purification / Q000592:standards
chemical_list: D005740:Gases; D055549:Volatile Organic Compounds