Multidimensional GC using planar microfluidic devices for the characterization of phenolic antioxidants in fuels

Abstract

A multidimensional gas chromatographic approach using planar microfluidic devices for Deans switching has been developed and implemented for the characterization of sterically hindered phenolic compounds used as antioxidants in fuels. Detection and quantitation was conducted with MS in selected ion monitoring mode. A complete analysis is conducted in less than 15 min with precision greater than 5.5% at 1 and 25 ppm w/w (ppm(w)). LODs of 50 ppb w/w (ppb(w)) or better in selected ion monitoring mode and a linear range of 100 ppb(w) to 100 ppm(w) with a correlation coefficient greater than 0.998 were attained for all analytes. Unique to this analytical configuration is the use of a mass spectrometer capable of monitoring the column effluent from either dimension by incorporating a high-temperature rotary valve and a three-port planar microfluidic device. High-molecular-weight (C25-C40) fuel contaminants eluting from the first column can be selectively sent to the mass spectrometer for profile characterization in scan mode. These compounds would otherwise be retained substantially by the low-phase-ratio analytical column employed in the second dimension.

Trace-level screening of dichlorophenols in processed dairy milk by headspace gas chromatography

“…Underivatized chlorinated and alkylated phenols have been successfully chromatographed using a number of classical column stationary phases . However, due to the acidic nature of the phenolic compounds, surface adsorption and hydrogen bonding with the active sites on the stationary phases, distorted peak symmetry and higher detection limit are often encountered . Figure shows a chromatogram of 1 μg/g of 2,4‐dichlorophenol and 2,6‐dichlorophenol in methanol using a 15 m × 0.32 mm‐id × 1.2 μm CP‐Sil 5CB MS column.…”

Characterization of selected oxidation inhibitors in transformer oils by multidimensional gas chromatography with capillary flow technology

“…[7][8][9][10] Recently, similar phenolic compounds were investigated in fuels using an MDGC approach, which included a high phase ratio non-polar column as the rst dimension and a polar column as the second analytical column. 11 Stemming from this work, a rst dimension, non-polar column was chosen. Additionally, this column contained a high phase ratio (b ¼ 625) to quickly elute the oxidation inhibitors and not permanently retain the larger molecular weight components of the transformer oil.…”

Multidimensional gas chromatography beyond simple volatiles separation

“…52,[57][58][59] A shorter normal bore 1 D column was used for high temperature (HT) GC Â GC and GC-GC (4300 1C) to resolve high boiling solutes. [60][61][62][63] Further column combinations incorporating three or more GC columns allow ultrahigh resolution analysis, namely smart 3D micro-GC, 34 comprehensive 3D GC, 51 and preparative 3D GC, 52,64 integrated/switchable GC-GC with GC Â GC, 65,66 and hybrid (sequential) GC Â GC-GC. 67…”