Hybrid integration of injector and detector functions for microchip gas chromatography

Abstract

Hybrid microchips containing high aspect ratio gas chromatograph (GC) columns with an integrated on-chip split injection and a flame ionization detector were developed. Two different column configurations, spiral and serpentine, both 1 m long by 50 μm wide and 500 μm tall, were fabricated out of electrodeposited nickel. The hybrid chip allowed injection plugs on the order of 1-2 ms, which lowered the height equivalent to theoretical plates (HETP) and allowed a comparison of system level band broadening between the two column configurations. The gas phase band broadening was estimated by measuring the flow characteristics and peak broadening of an unretained compound, and the results were compared with kinetic models. Experimental results show that both spiral and serpentine column layouts had similar flow and band broadening, suggesting that gas phase band broadening may be independent of column layout. The necessity for narrow injection bands for fast micro-chip chromatographic analysis was demonstrated, which emphasized the importance of component integration in designing powerful micro-analytical systems.

A Binder Jet Printed, Stainless Steel Preconcentrator as an In-Line Injector of Volatile Organic Compounds

“…In order for micro-PCs to function in a chemical analysis system, they need to be connected to other components such as separation columns and sensors. Unless they are monolithically integrated [18], each of these components is modularly integrated and typically connected via polyimide-coated glass capillary tubing [46,47]. The majority of micro-PCs are silicon based, which is brittle and difficult to machine for fluidic connections.…”

Micro Gas Chromatography: An Overview of Critical Components and Their Integration

“…The authors attribute the enhanced separation performance of the serpentine design to favorable hydrodynamic flow as well as thinner and more homogeneous stationary-phase coating in serpentine configuration. Bhushan et al, 77 using methane as an unretained marker, showed that circular-spiral and serpentine column layouts exhibit similar flow and band broadening. The band broadening effect for retained compounds was not evaluated.…”