Isolation And Analyses Of Organic Compounds In Lingwu Bituminous Coal

Isolation and analyses of organic components in coals play an important rule in coal chemistry research and coal effcient utilization. To investigate the organic chemical compositions in bituminous coals, in this study, Lingwu bituminous coal from West China was extracted sequentially with methanol, petroleum ether, benzene, acetone and acetone/carbon disulfide (CS2) mixture. The classification extracts were analysed by GC/MS first, and then separated and purified through the silica-gel and Sephadex LH-20 gelatin column chromatographies. The isolated components were identified by FTIR, GC/MS, LC/MS, 1H NMR and 13C NMR analyses.The GC/MS analysis results of coal classification extracts demonstrate all extracts are complex mixtures containing alkanes, arenes and heteroatomic organic compounds. 103 compounds were detected from the mathanol-extractable fraction. 75 compounds were detected from the petroleum ether-extractable fraction. From benzene-extractable fraction, 185 compounds were detected. From acetone- extractable fraction, 78 compounds were detected. And 112 compounds were detected from the acetone/CS2-extractable fraction.With the further separation and purification of every classification extract by silica-gel and Sephadex LH-20 gelatin column chromatographies, 18 compounds were isolated and identified as bis(2-ethylheptyl) phthalate, bis(2-ethylheptyl) terephthalate, methyl tetracosanoate, methyl hexacosanoate, tetracosanoic acid, hexacosanic acid, benz[e]acephenanthrylene, tricosanic acid and 18-ethyl-17- (hexan-2'-yl)docosanoic acid, 4,4'-Ethylenebis(2,6-di-tert-butylphenol), Heptyl pentan-2-yl phthalate, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 2-[(2-ethylhexyl- oxy) carbonyl]benzoic acid, 2,2'-[ethane-1,2-diylbis(oxy)]bis(ethane-2,1-diyl) bis(2- ethylhexanoate), 2,6-di-tert-butyl-4-methylphenylmethylcarbamate, 5,14- dimethyl- 5,14-dihydronaphtho[2,3-b]phenazine by GC/MS, FTIR, LC/MS, 1H NMR and 13C NMR analyses, and two compounds were not identified through different spectra. All the compounds were isolated and identified from the bituminous coals for the first time, bis(2-ethylheptyl) terephthalate and 18-ethyl-17-(hexan-2'-yl) docosanoic acid are new compounds.Further more, a Colourless Oil Liquid, a white acerate crystals containing some alkanes, a white tabular crystals consisting of some fatty acid esters and a white powder crystals in which some fatty acids exist were isolated and analysed by GC/MS for the first time.Through this research, a study method of"classification extract of bituminous coal- separation with silica-gel and gelatin column chromatographies- identification of the isolated compounds by FTIR, GC/MS, LC/MS, 1H NMR and 13C NMR analyses"was established and proved to be a practical approach toward separable and non-destructive identification of some organic compounds in bituminous coals for coal chemistry research.