Characterizations of the Extracts from Geting Bituminous Coal by Spectrometries

Abstract

Geting bituminous coal (GBC) was sequentially extracted with petroleum ether, carbon disulfide (CDS), methanol, acetone, and isometric CDS/acetone mixed solvent at room temperature to afford extracts 1–5 (E₁–E₅) and residue. Detailed characterizations of the extracts were performed with a gas chromatography/mass spectrometer (GC/MS), Fourier transform infrared (FTIR) spectrometer, and direct analysis in real-time ionization source (DARTIS) coupled to an ion-trap mass spectrometer (ITMS). GBC and its residue were also analyzed with the FTIR spectrometer. Particle sizes of the residue were significantly reduced compared to those of GBC according to the observation with a scanning electron microscope. Arenes with 1–4 rings and more condensed arenes were enriched into E₁ and E₂, respectively, while more heteroatom-containing organic species were detected in other extracts, especially in E₃ and E₄ according to GC/MS analysis. The extracts, especially E₁–E₄, contain more aliphatic moieties and less aromatic moieties compared to GBC and its residue based on FTIR analysis. DARTIS/ITMS proved to be a powerful tool for analyzing thermally labile and/or involatile species, which are difficult to be identified with GC/MS, in the extracts