Characterization of Novel Materials as Platforms for Performing Microfluidic Gas Chromatography
Date
2013-04-23
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Abstract
Analytical Gas Chromatography (GC) separation techniques are constantly being developed to reduce analysis time and cost as well as improve sensitivity and accuracy. One such development is the fabrication of miniaturized microfluidic columns for use in GC. There are vast reports of miniaturized columns fabricated in silicon and even other polymeric materials. While these devices show good separation efficiency, they lack physical robustness and the thermal stability demanded by GC. Alternatively, Low Temperature Co-fired Ceramics (LTCC) and titanium are novel materials that show promise for use in microfluidic GC column fabrication. They offer advantages such as low cost, ease of fabrication, and additionally, these materials are quite strong and can withstand the high temperatures required in GC. LTCC together with titanium metals have been studied and characterized as alternative platforms for microfluidic GC in this thesis. Both LTCC and titanium tiles produced good results that compared well with commercially available GC columns. For example, a 7.5m long channel within an 11 cm x 5.5 cm LTCC tile under optimum conditions generated theoretical plates for a dodecane test analyte of about 14327 compared to 4507 for a 7.5 m long commercial capillary column. Similarly, a 15m long channel within a 15 cm x 8 cm titanium tile produced 10377 plates for the same test analyte. Both of these tiles showed high resolving power, yielding benzene – toluene resolutions of about 14.07 and 8.29 respectively for LTCC and titanium. Peak capacity was also probed using temperature programming with a simple nC8 – nC20 alkane mixture. A cumulative peak capacity of about 53 was obtained for the LTCC tile while the titanium tile gave a value of 48. Polar analyte separations on both often produced peaks with a greater degree of tailing. Additionally, packed columns fabricated on these materials were also investigated, and produced good separation efficiency with negligible flow restriction. For example, a 10 cm long channel within a 5.5 cm x 2.5 cm LTCC tile packed with 5µm C18 particles generated 2710 plates per meter. Likewise, a 10 cm long channel within a 9 cm x 5 cm titanium tile packed with 1.7µm C18 particles also produced 8430 plates per meter; a three fold increase. Neither displayed any adverse effects from operating the tiles up to 60 atm of carrier gas pressure. Results indicate that LTCC and titanium make excellent platforms for microfluidic GC. Further exploration of their properties in this area will be useful.
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Keywords
Chemistry--Analytical
Citation
Darko, E. (2013). Characterization of Novel Materials as Platforms for Performing Microfluidic Gas Chromatography (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25281