Title: | Comprehensive two-dimensional gas chromatographic separations with a microfabricated thermal modulator |
Author(s): | Serrano G; Paul D; Kim SJ; Kurabayashi K; Zellers ET; |
Address: | "Center for Wireless Integrated MicroSensing and Systems, University of Michigan, Ann Arbor, Michigan 48109, USA" |
ISSN/ISBN: | 1520-6882 (Electronic) 0003-2700 (Linking) |
Abstract: | "Rapid, comprehensive two-dimensional gas chromatographic (GC x GC) separations by use of a microfabricated midpoint thermal modulator (muTM) are demonstrated, and the effects of various muTM design and operating parameters on performance are characterized. The two-stage muTM chip consists of two interconnected spiral etched-Si microchannels (4.2 and 2.8 cm long) with a cross section of 250 x 140 mum(2), an anodically bonded Pyrex cap, and a cross-linked wall coating of poly(dimethylsiloxane) (PDMS). Integrated heaters provide rapid, sequential heating of each muTM stage, while a proximate, underlying thermoelectric cooler provides continual cooling. The first-dimension column used for GC x GC separations was a 6 m long, 250 mum i.d. capillary with a PDMS stationary phase, and the second-dimension column was a 0.5 m long, 100 mum i.d. capillary with a poly(ethylene glycol) phase. Using sets of five to seven volatile test compounds (boiling point =174 degrees C), the effects of the minimum (T(min)) and maximum (T(max)) modulation temperature, stage heating lag/offset (O(s)), modulation period (P(M)), and volumetric flow rate (F) on the quality of the separations were evaluated with respect to several performance metrics. Best results were obtained with a T(min) = -20 degrees C, T(max) = 210 degrees C, O(s) = 600 ms, P(M) = 6 s, and F = 0.9 mL/min. Replicate modulated peak areas and retention times were reproducible to <5%. A structured nine-component GC x GC chromatogram was produced, and a 21 component separation was achieved in <3 min. The potential for creating portable muGC x muGC systems is discussed" |
Keywords: | "Chromatography, Gas/*instrumentation/*methods Equipment Design Kinetics Microtechnology/*instrumentation/*methods Reproducibility of Results *Temperature Volatile Organic Compounds/chemistry;" |
Notes: | "MedlineSerrano, Gustavo Paul, Dibyadeep Kim, Sung-Jin Kurabayashi, Katsuo Zellers, Edward T eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2012/08/07 Anal Chem. 2012 Aug 21; 84(16):6973-80. doi: 10.1021/ac300924b. Epub 2012 Jul 31" |