Application of mass spectrometry in the characterization of chemicals in coal‐derived liquids

Coal‐derived liquids (CDLs) are primarily generated from pyrolysis, carbonization, gasification, direct liquefaction, low‐temperature extraction, thermal dissolution, and mild oxidation. CDLs are important feedstocks for producing value‐added chemicals and clean liquid fuels as well as high performance carbon materials. Accordingly, the compositional characterization of chemicals in CDLs at the molecular level with advanced analytical techniques is significant for the efficient utilization of CDLs. Although reviews on advancements have been rarely reported, great progress has been achieved in this area by using gas chromatography/mass spectrometry (GC/MS), two‐dimensional GC‐time of flight mass spectrometry (GC × GC‐TOFMS), and Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS). This review focuses on characterizing hydrocarbon, oxygen‐containing, nitrogen‐containing, sulfur‐containing, and halogen‐containing chemicals in various CDLs with these three mass spectrometry techniques. Small molecular (