Merck

Axial thermal gradients in microchip gas chromatography.

Journal of chromatography. A (2014-12-06)
Anzi Wang, Sampo Hynynen, Aaron R Hawkins, Samuel E Tolley, H Dennis Tolley, Milton L Lee
ABSTRACT

Fabrication technologies for microelectromechanical systems (MEMS) allow miniaturization of conventional benchtop gas chromatography (GC) to portable, palm-sized microfabricated GC (μGC) devices, which are suitable for on-site chemical analysis and remote sensing. The separation performance of μGC systems, however, has not been on par with conventional GC. Column efficiency, peak symmetry and resolution are often compromised by column defects and non-ideal injections. The relatively low performance of μGC devices has impeded their further commercialization and broader application. In this work, the separation performance of μGC columns was improved by incorporating thermal gradient gas chromatography (TGGC). The analysis time was ∼20% shorter for TGGC separations compared to conventional temperature-programmed GC (TPGC) when a wide sample band was introduced into the column. Up to 50% reduction in peak tailing was observed for polar analytes, which improved their resolution. The signal-to-noise ratios (S/N) of late-eluting peaks were increased by 3-4 fold. The unique focusing effect of TGGC overcomes many of the previous shortcomings inherent in μGC analyses.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
2-Octanol, ≥97%, FG
Sigma-Aldrich
Carbon disulfide, anhydrous, ≥99%
Sigma-Aldrich
Undecane, ≥99%
Sigma-Aldrich
Nonylamine, ≥99.5% (GC)
Sigma-Aldrich
Nonylamine, 98%
Sigma-Aldrich
Undecane, ≥99%
Sigma-Aldrich
Decane, anhydrous, ≥99%
Sigma-Aldrich
Dicumyl peroxide, 98%
Supelco
Decane, analytical standard
Supelco
Decane, analytical standard
Sigma-Aldrich
Decane, ≥95%
Supelco
Undecane, analytical standard
Sigma-Aldrich
Carbon disulfide, suitable for HPLC, ≥99.9%
Sigma-Aldrich
Carbon disulfide, ReagentPlus®, low benzene, ≥99.9%
Sigma-Aldrich
Carbon disulfide, ReagentPlus®, purified by redistillation, ≥99.9%
Sigma-Aldrich
Carbon disulfide, suitable for IR spectroscopy, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.9% (GC)
Sigma-Aldrich
Carbon disulfide, ACS reagent, ≥99.9%
Sigma-Aldrich
Carbon disulfide, ACS reagent, ≥99.9%
Sigma-Aldrich
2-Octanol, 97%
Sigma-Aldrich
Decane, ReagentPlus®, ≥99%
Sigma-Aldrich
Pentane, suitable for HPLC, ≥99.0%
Supelco
2,4,6-Trichlorophenol, certified reference material, TraceCERT®
Sigma-Aldrich
Carbon disulfide solution, 5 M in THF
Supelco
Density Standard 749 kg/m3, H&D Fitzgerald Ltd. Quality
Sigma-Aldrich
Tributyl phosphate, ≥99%
Sigma-Aldrich
Tributyl phosphate, 97%
Sigma-Aldrich
Dodecane, anhydrous, ≥99%
Sigma-Aldrich
2,4,6-Trichlorophenol, 98%
Sigma-Aldrich
Pentane, anhydrous, ≥99%
Supelco
Pentane, analytical standard