Open tubular supercritical fluid chromatography (ot-SFC) applied to the separation of coal-derived products obtained by supercritical fluid extraction (SFE)

This work describes the construction and evaluation of a simple and versati le capillary supercritical fluid chromatographic (SFC) system and its appli cation to the analysis of liquid fuels obtained by SFE. The modular supercr itical fluid chromatography (SFC) system uses a syringe pump, a fused silic a capillary column (100 mu m i.d., coated with a 0.2-mu m thick film of 5% phenylpolymethylsiloxane), a FID detector, and a high pressure injection va lve with a 60-nL internal loop. Coal-derived samples were obtained by super critical fluid extraction (SFE) of a Brazilian high-inertinite coal from Am ando Simoes mine, located in Parana state (Brazil) using toluene as solvent and operating in the static mode. SFE was Followed by preparative liquid c hromatography fractionation into eight discrete fractions (PLC-8 method). T wo of those fractions (F-2 and F-8) were used to evaluate the proposed set- up. The system described proved to be simple, easy-to-use, and versatile wh en used in the analysis of a range of samples from low molecular weight-low volatility (F-2) to higher molecular weight-high polarity asphaltols (F-8) .