The products in the water-soluble portion from mild oxidation of Jincheng No. 15 anthracite in aqueous hydrogen peroxide were analyzed with a gas chromatograph/quadrupole time-of-flight-mass spectrometer (GC/QTOF-MS) along with theoretical calculation for the first time. A series of heteroatom(s)-containing components were identified by comparing their mass spectra with NIST11 library data. Moreover, two organosulfur compounds without matched library mass spectra were inferred according to their tandem mass spectra and the formation of their fragmental ions was convincingly explained by energy calculation based on density functional theory. The investigation suggests that GC/QTOF-MS analysis combined with theoretical calculation would be a powerful tool for identifying unknown compounds in complicated mixtures from coals or their derivates. (C) 2014 Elsevier Ltd. All rights reserved.