Isolation of one-ring aromatics in shale oil by Sephadex LH-20 gel

Abstract

The liquid chromatographic procedure previously reported by Clark et al. (Clark, B.R.; Ho, C.H.; Jones, A.R.; Anal. Chem. 49: 1766 (1977)) was followed in fractionating shale oil hydrocarbons on Sephadex LH-20 gel. The major components of the gas chromatogram of the H-bonded fraction after silica gel treatment were identified by mass spectrometry as mostly one-ring aromatics plus a few two-ring aromatic hydrocarbons. The behavior of paraffinic, olefinic and aromatic hydrocarbons on tetrhydrofuran treated Sephadex LH-20 was previously reported by Hsich et al. (Hisch, B.C.B.; Wood, R.E.; Anderson, L.L.; Hill, G.R.; Anal. Chem. 41: 1066 (1969)). They observed that paraffinic compounds followed a simple curvilinear function with olefinic compounds following the same trend from high to low number, with an icrease in elution volume. However, homologous aromatic compounds exhibited different slopes dependent on molecular size and configuration. For aromatic hydrocarbons of one and two rings, elution volumes greater than the volumes required for C/sub 5/ to C/sub 30/ paraffins and olefins were indicated; this should resolve the one-ring aromatics and some two-ring components from the C/sub 5/ to C/sub 30/ paraffins and olefins.