Separation and analysis of organic compounds in an Erdos coal

A subbitumious coal from Erdos, Inner Mongolia, China, was extracted with isometric CS2/tetrahydrofuran mixed solvent. The extract was separated by silica-gel column chromatography. A series of long-chain normal alkanes, monoaromatic steranes, polycyclic arenes and heteroatom-containing species in the extract were concentrated to large extents. In addition, abiettriene and retene were separated in high purities.